Search

We present an optical transmission spectrum of the hot Jupiter WASP-101b. We observed three primary transits with Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph, covering a wavelength range from 0.3 to 1 $\mu$m. The observations suffer from significant systematics that we model using Gaussian Processes. Kernel selection for the Gaussian Processes is performed in a data-driven approach through Bayesian model comparison. We find a flat and featureless transmission spectrum, corroborating a previous measurement obtained with HST/Wide-Field Camera 3 in the 1–1.7 $\mu$m range. The spectrum is consistent with high-altitude clouds located at less than 100 $\mu$bar. This cloud layer completely blocks our view into deeper parts of the atmosphere and makes WASP-101b the cloudiest gas giant observed so far. We compute a series of temperature-pressure profiles for WASP-101b and compare these to condensation curves for cloud particles, which match clouds composed of silicates. We also include 13 transits observed with Transiting Exoplanet Survey Satellite and use these to refine system parameters.

We thank the anonymous reviewer for the helpful comments and suggestions. We also thank Dr. K. G. Isaak, the ESA CHEOPS Project Scientist, responsible for the ESA CHEOPS Guest Observers Programme, for the helpful discussions and support. This work was supported by the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, the PRODEX Experiment Agreement No. 4000137122 between the ELTE University and the European Space Agency (ESA-D/SCI-LE-2021-0025), the City of Szombathely under agreement No. 67.177-21/2016, and by the VEGA grant of the Slovak Academy of Sciences No. 2/0031/22. TP acknowledges support from the Slovak Research and Development Agency -contract No. APVV-20-0148. AC acknowledges financial support from the State Agency for Research of the Spanish MCIU through the `Center of Excellence Severo Ochoa' award for the Instituto de Astrophysics of Andalusia (SEV-2017-0709). CHEOPS is an ESA mission in partnership with Switzerland with important contributions to the payload and the ground segment from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden, and the UK. The authors acknowledge the observing time awarded within the CHEOPS Guest Observers Programme No. 1 (AO-1) and the support from the Science Operations Centre. This paper includes data collected with the TESS mission, obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the TESS mission is provided by the NASA Explorer Program. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 526555. This work has used data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement., Rapidly rotating early-type main-sequence stars with transiting planets are interesting in many aspects. Unfortunately, several astrophysical effects in such systems are not well understood yet. Therefore, we performed a photometric mini-surv e y of three rapidly rotating stars with transiting planets, namely KEL T -17b, KEL T -19Ab, and KEL T -21b, using the Characterising Exoplanets Satellite ( CHEOPS ), complemented with Transiting Exoplanet Survey Satellite ( TESS ) data, and spectroscopic data. We aimed at investigating the spin-orbit misalignment and its photometrical signs, therefore the high-quality light curves of the selected objects were tested for transit asymmetry, transit duration variations, and orbital precession. In addition, we performed transit time variation analyses, obtained new stellar parameters, and refined the system parameters. For KEL T -17b and KEL T - 19Ab, we obtained significantly smaller planet radius as found before. The gravity-darkening effect is very small compared to the precision of CHEOPS data. We can report only on a tentative detection of the stellar inclination of KEL T -21, which is about 60 deg. In KEL T -17b and KEL T -19Ab, we were able to exclude long-term transit duration variations causing orbital precession. The shorter transit duration of KEL T -19Ab compared to the disco v ery paper is probably a consequence of a smaller planet radius. KEL T -21b is promising from this viewpoint, but further precise observations are needed. We did not find any convincing evidence for additional objects in the systems., National Research, Development & Innovation Office (NRDIO) - Hungary K-125015, ELTE University 4000137122, European Space Agency European Commission 4000137122 ESA-D/SCI-LE-2021-0025, City of Szombathely 67.177-21/2016, Slovak Academy of Sciences 2/0031/22 Slovak Research and Development Agency APVV-20-0148, Spanish Government SEV-2017-0709, CHEOPS Guest Observers Programme 1 (AO-1), Science Operations Centre, National Aeronautics & Space Administration (NASA) NAS 526555

The massive outburst of the comet 17P/Holmes in October 2007 is the largest known outburst by a comet thus far. We present a new comprehensive model describing the evolution of the dust trail produced in this phenomenon. The model comprises of multiparticle Monte Carlo approach including the solar radiation pressure effects, gravitational disturbance caused by Venus, Earth and Moon, Mars, Jupiter and Saturn, and gravitational interaction of the dust particles with the parent comet itself. Good accuracy of computations is achieved by its implementation in Orekit, which executes Dormad-Prince numerical integration methods with higher precision. We demonstrate performance of the model by simulating particle populations with sizes from 0.001 mm to 1 mm with corresponding spherically symmetric ejection speed distribution, and towards the Sun outburst modelling. The model is supplemented with and validated against the observations of the dust trail in common nodes for 0.5 and 1 revolutions. In all cases, the predicted trail position showed a good match to the observations. Additionally, the hourglass pattern of the trail was observed for the first time within this work. By using variations of the outburst model in our simulations, we determine that the assumption of the spherical symmetry of the ejected particles leads to the scenario compatible with the observed hourglass pattern. Using these data, we make predictions for the two-revolution dust trail behavior near the outburst point that should be detectable by using ground-based telescopes in 2022., Comment: 70 pages, 29 main figures, open access in MNRAS

We present an analysis of the optical and UV properties of AT 2020wey, a faint and fast tidal disruption event (TDE) at 124.3 Mpc. The light curve of the object peaked at an absolute magnitude of $M_{g} = -17.45$ mag and a maximum bolometric luminosity of $L_{\rm peak}=(8.74\pm0.69)\times10^{42}$ erg s$^{-1}$, making it comparably faint with iPTF16fnl, the faintest TDE to date. The time from the last non-detection to the $g$-band peak is 22.94 $\pm$ 2.03 days and the rise is well described by $L\propto t^{1.8}$. The decline of the bolometric light curve is described by a sharp exponential decay steeper than the canonical $t^{-5/3}$ power law, making AT 2020wey the fastest declining TDE to date. Multi-wavelength fits to the light curve indicate a complete disruption of a star of $M_*=0.11M_{\odot}$ by a black hole of $M_{\rm BH}=10^{6.46}M_{\odot}$. Our spectroscopic dataset reveals broad ($\sim10^{4}$ km s$^{-1}$) Balmer and He II $\lambda$4686 lines, with H$\alpha$ reaching its peak with a lag of $\sim8.2$ days compared to the continuum. In contrast to previous faint and fast TDEs, there are no obvious Bowen fluorescence lines in the spectra of AT 2020wey. There is a strong correlation between the MOSFIT-derived black hole masses of TDEs and their decline rate. However, AT 2020wey is an outlier in this correlation, which could indicate that its fast early decline may be dictated by a different physical mechanism than fallback. After performing a volumetric correction to a sample of 30 TDEs observed between 2018 and 2020, we conclude that faint TDEs are not rare by nature and that they should constitute up to $\sim$ 50 - 60 % of the entire population and their numbers could alleviate some of the tension between the observed and theoretical TDE rate estimates. We calculate the optical TDE luminosity function and we find a steep power-law relation $dN/dL_{g} \propto {L_{g}}^{-2.36}$., Comment: Accepted for publication to A&A (21/02/2023)

Thanks to the advent of large-scale optical surveys, a diverse set of flares from the nuclear regions of galaxies has recently been discovered. These include the disruption of stars by supermassive black holes at the centers of galaxies - nuclear transients known as tidal disruption events (TDEs). Active galactic nuclei (AGN) can show extreme changes in the brightness and emission line intensities, often referred to as changing-look AGN (CLAGN). Given the physical and observational similarities, the interpretation and distinction of nuclear transients as CLAGN or TDEs remains difficult. One of the obstacles of making progress in the field is the lack of well-sampled data of long-lived nuclear outbursts in AGN. Here, we study PS16dtm, a nuclear transient in a Narrow Line Seyfert 1 (NLSy1) galaxy, which has been proposed to be a TDE candidate. Our aim is to study the spectroscopic and photometric properties of PS16dtm, in order to better understand the outbursts originating in NLSy1 galaxies. Our extensive multiwavelength follow-up that spans around 2000 days includes photometry and spectroscopy in the UV/optical, as well as mid-infrared (MIR) and X-ray observations. Furthermore, we improved an existing semiempirical model in order to reproduce the spectra and study the evolution of the spectral lines. The UV/optical light curve shows a double peak at $\sim50$ and $\sim100$ days after the first detection, and it declines and flattens afterward, reaching preoutburst levels after 2000 days of monitoring. The MIR light curve rises almost simultaneously with the optical, but unlike the UV/optical which is approaching the preoutburst levels in the last epochs of our observations, the MIR emission is still rising at the time of writing. The optical spectra show broad Balmer features and the strongest broad Fe II emission ever detected in a nuclear transient. [abridged], Accepted for publication in A&A, 19 pages and 18 figures

We present new [O III] 88 ${\rm \mu}$m observations of five bright $z \sim 7$ Lyman-break galaxies spectroscopically confirmed by ALMA through the [C II] 158 ${\rm \mu}$m line, unlike recent [O III] detections where Lyman-${\rm \alpha}$ was used. This nearly doubles the sample of Epoch of Reionisation galaxies with robust ($5 \sigma$) detections of [C II] and [O III]. We perform a multi-wavelength comparison with new deep HST images of the rest-frame UV, whose compact morphology aligns well with [O III] tracing ionised gas. By contrast, we find more spatially extended [C II] emission likely produced in neutral gas, as indicated by a [N II] 205 ${\rm \mu}$m non-detection in one source. We find a positive correlation between the equivalent width of the optical [O III] and H${\rm \beta}$ lines and the [O III]/[C II] ratio, as seen in local metal-poor dwarf galaxies. Cloudy models of a nebula of typical density harbouring a young stellar population with a high ionisation parameter appear to adequately reproduce the far-infrared lines. Surprisingly, however, our models fail to reproduce the strength of [O III] 88 ${\rm \mu}$m, unless we assume an ${\rm \alpha}$/Fe enhancement and a near-solar nebular oxygen abundance. On spatially resolved scales, we find [O III]/[C II] shows a tentative anti-correlation with infrared excess, $L_{\rm IR}/L_{\rm UV}$, also seen on global scales in the local Universe. Finally, we introduce the far-infrared spectral energy distribution fitting code MERCURIUS to show that dust-continuum measurements of one source appear to favour a low dust temperature coupled with a high dust mass. This implies a high stellar metallicity yield and may point towards the need of dust production or grain-growth mechanisms beyond supernovae., Comment: 23 pages, 11 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society

Between 2010 and 2017 we have collected new optical and radar observations of the potentially hazardous asteroid (2102)~Tantalus from the ESO NTT and Danish telescopes at the La Silla Observatory and from the Arecibo planetary radar. The object appears to be nearly spherical, showing a low amplitude light-curve variation and limited large-scale features in the radar images. The spin-state is difficult to constrain with the available data; including a certain light-curve subset significantly changes the spin-state estimates, and the uncertainties on period determination are significant. Constraining any change in rotation rate was not possible, despite decades of observations. The convex lightcurve-inversion model, with rotational pole at ${\lambda}=210{\pm}41${\deg} and ${\beta}=-30{\pm}35${\deg}, is more flattened than the two models reconstructed by including radar observations: with prograde (${\lambda}=36{\pm}23${\deg}, ${\beta}=30{\pm}15${\deg}), and with retrograde rotation mode (${\lambda}=180{\pm}24${\deg}, ${\beta}=-30{\pm}16${\deg}). Using data from WISE we were able to determine that the prograde model produces the best agreement in size determination between radar and thermophysical modelling. Radar measurements indicate possible variation in surface properties, suggesting one side might have lower radar albedo and be rougher at centimetre-to-decimetre scale than the other. However, further observations are needed to confirm this. Thermophysical analysis indicates a surface covered in fine-grained regolith, consistent with radar albedo and polarisation ratio measurements. Finally, geophysical investigation of the spin-stability of Tantalus shows that it could be exceeding its critical spin-rate via cohesive forces., Comment: Main paper: 14 pages and 12 figure, Appendix: 13 pages and 12 figues

To investigate the feasibility of ancillary target observations with ESA's Ariel mission, we compiled a list of potentially interesting young stars: FUors, systems harbouring extreme debris discs and a larger sample of young stellar objects showing strong near/mid-infrared excess. These objects can be observed as additional targets in the waiting times between the scheduled exoplanet transit and occultation observations. After analyzing the schedule for Ariel an algorithm was constructed to find the optimal target to be observed in each gap. The selection was mainly based on the slew and stabilization time needed to observe the selected YSO, but it also incorporated the scientific importance of the targets and whether they have already been sufficiently measured. After acquiring an adequately large sample of simulation data, it was concluded that approximately 99.2% of the available -- at least one hour long -- gaps could be used effectively. With an average slewing and stabilization time of about 16.7 minutes between scheduled exoplanet transits and ancillary targets, this corresponds to an additional $2881 \pm 56$ hours of active data gathering. When this additional time is used to observe our selected 200 ancillary targets, a typical signal-to-noise ratio of $\sim$10$^4$ can be achieved along the whole spectral window covered by Ariel., Comment: Accepted for publication in Experimental Astronomy

The authors thank the anonymous referee for the useful comments that improved the article. CMC acknowledges the support of CNPq, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico Brazil, process number 141714/2016-6. This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior - Brasil (CAPES) - Finance Code 001. LB acknowledges support fromCONICYT (Comision Nacional de Investigacion Cientifica y Tecnologica) project Basal AFB-170002. EM acknowledges support from the Brazilian agencies FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, grant 2014/22095-6) and CNPq (grant 150465/2019-0). MC acknowledges the financial support from theEuropean Union'sHorizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement no 872081; from the Spanish National Research, Development, and Innovation plan (RDI plan) under the project PID2019-104002GB-C21; the Consejeria de Conocimiento, Investigacion y Universidad, Junta de Andalucia and European Regional Development Fund (ERDF), ref. SOMM17/6105/UGR; the Ministerio de Ciencia, Innovacion y Universidades (ref. COOPB20364); and by the Centro de Estudios Avanzados en Fisica, Matematicas y Computacion (CEAFMC) of the University of Huelva., Isocyanic acid (HNCO) is a simple molecule with a potential to form prebiotic and complex organic species. Using a spectral survey collected with the Atacama Pathfinder EXperiment, in this work we report the detection of 42 transitions of HNCO in the hot molecular core/outflow G331.512-0.103 (hereafter G331). The spectral lines were observed in the frequency interval ∼160–355 GHz. By means of Local Thermodynamic Equilibrium analyses, applying the rotational diagram method, we studied the excitation conditions of HNCO. The excitation temperature and column density are estimated to be Tex= 58.8 ± 2.7 K and N = (3.7 ± 0.5) × 1015 cm−2, considering beam dilution effects. The derived relative abundance is between (3.8 ± 0.5) × 10−9 and (1.4 ± 0.2) × 10−8. In comparison with other hot molecular cores, our column densities and abundances are in agreement. An update of the internal partition functions of the four CHNO isomers: HNCO; cyanic acid, HOCN; fulminic acid, HCNO; and isofulminic acid, HONC is provided. We also used the astrochemical code NAUTILUS to model and discuss HNCO abundances. The simulations could reproduce the abundances with a simple zero-dimensional model at a temperature of 60 K and for a chemical age of ∼105 yr, which is larger than the estimated dynamical age for G331. This result could suggest the need for a more robust model and even the revision of chemical reactions associated with HNCO., Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) 141714/2016-6, Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) 001, Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) Basal AFB-170002, Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) 2014/22095-6, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) 150465/2019-0, European Union'sHorizon 2020 research and innovation program under the Marie Sklodowska-Curie grant 872081, Spanish National Research, Development, and Innovation plan (RDI plan) PID2019-104002GB-C21, Consejeria de Conocimiento, Investigacion y Universidad, Junta de Andalucia, European Commission SOMM17/6105/UGR, Ministerio de Ciencia, Innovacion y Universidades COOPB20364, Centro de Estudios Avanzados en Fisica, Matematicas y Computacion (CEAFMC) of the University of Huelva

This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.00650.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic ofKorea), in cooperationwith theRepublic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The authors are grateful to Krajnovi ' c et al. for the Kinemetry code. The authors thank the referee, Prof. JeffreyKenney, for valuable comments and suggestions that improved this paper. The authors also thank the support of the Astronomical Data Center of the National Astronomical Observatory of Japan, and Anthony Moraghan for assistance on the computational facilities and resources at Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). DE acknowledges support from a Beatriz Galindo senior fellowship (BG20/00224) from the SpanishMinistry of Science and Innovation. YTW wishes to thank Dr. Yu-Nung Su and Dr. Sheng-Yuan Liu for hosting her visit at ASIAA in 2020., We present results obtained from ALMA CO (2–1) data of the double-barred galaxy NGC3504.With three times higher angular resolution (∼0. 8) than previous studies, our observations reveal an inner molecular gas bar, a nuclear ring, and four inner spiral arm-like structures in the central 1-kpc region. Furthermore, the CO emission is clearly aligned with the two dust lanes in the outer bar region, with differences in shape and intensity between them. The total molecular gas mass in the observed region (50 arcsec×57 arcsec) is estimated to be∼3.1 × 109M , which is 17 per cent of the stellarmass.We used the Kinemetry package to fit the velocity field and found that circular motion strongly dominates at R = 0.3–0.8 kpc, but radial motion becomes important at R < 0.3 kpc and R = 1.0–2.5 kpc, which is expected due to the presence of the inner and outer bars. Finally, assuming that the gas moves along the dust lanes in the bar rotating frame, we derived the pattern speed of the outer bar to be 18 ± 5 kms−1 kpc−1, the average streaming velocities on each of the two dust lanes to be 165 and 221 km s−1, and the total mass inflow rate along the dust lanes to be 12M yr−1. Our results give a new example of an inner gas bar within a gas-rich double-barred galaxy and suggest that the formation of double-barred galaxies could be associated with the existence of such gas structures., Spanish Government BG20/00224

Increasing our knowledge of the orbits and compositions of Near-Earth Objects (NEOs) is important for a better understanding of the evolution of the Solar System and of life. The detection of serendipitous NEO appearances among the millions of archived exposures from large astronomical imaging surveys can provide a contribution which is complementary to NEO surveys. Using the AstroWISE information system, this work aims to assess the detectability rate, the achieved recovery rate and the quality of astrometry when data mining the ESO archive for the OmegaCAM wide-field imager at the VST. We developed an automatic pipeline that searches for the NEO appearances inside the AstroWISE environment. Throughout the recovery process, the pipeline uses several public web-tools to identify possible images that overlap with the position of NEOs, and acquires information on the NEOs predicted position and other properties (e.g., magnitude, rate and direction of motion) at the time of observations. We have recovered 196 appearances of NEOs from a set of 968 appearances predicted to be recoverable. It includes appearances for three NEOs which were on the impact risk list at that point. These appearances were well before their discovery. The subsequent risk assessment using the extracted astrometry removes these NEOs from the risk list. We estimate a detectability rate of 0.05 per NEO at an SNR>3 for NEOs in the OmegaCAM archive. Our automatic recovery rates are 40% and 20% for NEOs on the risk list and the full list, respectively. The achieved astrometric and photometric accuracy is on average 0.12 arcsec and 0.1 mag. These results show the high potential of the archival imaging data of the ground-based wide-field surveys as useful instruments for the search, (p)recovery and characterization of NEOs. Highly automated approaches, as possible using AstroWISE, make this undertaking feasible., 13 pages, 13 figures, accepted for publication in Astronomy & Astrophysics

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiere, Current and future imaging surveys require photometric redshifts (photo-zs) to be estimated for millions of galaxies. Improving the photo-z quality is a major challenge but is needed to advance our understanding of cosmology. In this paper we explore how the synergies between narrow-band photometric data and large imaging surveys can be exploited to improve broadband photometric redshifts. We used a multi-task learning (MTL) network to improve broadband photo-z estimates by simultaneously predicting the broadband photo-z and the narrow-band photometry from the broadband photometry. The narrow-band photometry is only required in the training field, which also enables better photo-z predictions for the galaxies without narrow-band photometry in the wide field. This technique was tested with data from the Physics of the Accelerating Universe Survey (PAUS) in the COSMOS field. We find that the method predicts photo-zs that are 13% more precise down to magnitude iAB < 23; the outlier rate is also 40% lower when compared to the baseline network. Furthermore, MTL reduces the photo-z bias for high-redshift galaxies, improving the redshift distributions for tomographic bins with z > 1. Applying this technique to deeper samples is crucial for future surveys such as Euclid or LSST. For simulated data, training on a sample with iAB < 23, the method reduces the photo-z scatter by 16% for all galaxies with iAB < 25. We also studied the effects of extending the training sample with photometric galaxies using PAUS high-precision photo-zs, which reduces the photo-z scatter by 20% in the COSMOS field, The PAU Survey is partially supported by MINECO under grants CSD2007-00060, AYA2015-71825, ESP2017-89838, PGC2018-094773, PGC2018-102021, SEV-2016-0588, SEV-2016-0597, MDM-2015-0509, PID2019-111317GB-C31 and Juan de la Cierva fellowship and LACEGAL and EWC Marie Sklodowska-Curie grant No 734374 and no.776247 with ERDF funds from the EU Horizon 2020 Programme, some of which include ERDF funds from the European Union. IEEC and IFAE are partially funded by the CERCA and Beatriu de Pinos program of the Generalitat de Catalunya. Funding for PAUS has also been provided by Durham University (via the ERC StG DEGAS-259586), ETH Zurich, Leiden University (via ERC StG ADULT279396 and Netherlands Organisation for Scientific Research (NWO) Vici grant 639.043.512), Bochum University (via a Heisenberg grant of the Deutsche Forschungsgemeinschaft (Hi 1495/5-1) as well as an ERC Consolidator Grant (No. 770935)), University College London, Portsmouth support through the Royal Society Wolfson fellowship and from the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 776247 EWC. The results published were also funded by the Polish National Agency for Academic Exchange (Bekker grant BPN/BEK/2021/1/00298/DEC/1), the European Union’s Horizon 2020 research and innovation programme under the Maria Skłodowska-Curie (grant agreement No 754510) and by the Spanish Ministry of Science and Innovation through Juan de la Cierva-formacion program (reference FJC2018-038792-I)

We test the impact of some systematic errors in weak lensing magnification measurements with the COSMOS 30-band photo-$z$ Survey flux limited to $I_{auto}, Comment: matches version accepted in MNRAS

Context. Contrary to the orthodox picture of planet formation resulting in a neatly ordered Solar System, exoplanet systems exhibit highly diverse orbits: short and long periods, circular and eccentric, well- and misaligned, and even retrograde orbits. In order to understand this diversity it is essential to probe key orbital parameters. Spin-orbit alignment is such a parameter and can provide information about the formation and migration history of the system. However, tidal circularisation and alignment might hamper interpretations of orbital eccentricity and obliquities in the context of planet formation and evolution for planets on orbits shorter than about 10 days. Aims. Here we aim to measure the projected stellar obliquity in the HD 332231system in which a warm (period ≈ 18.7 days) giant planet orbits a bright F star on a circular orbit. Methods. We observed the system during a transit with the HARPS-N spectrograph and obtained data on the Rossiter-McLaughlin effect. We analysed the spectroscopic transit data together with new TESS photometry employing three different analysis methods. Results. The results from the different approaches are fully consistent. We find a projected obliquity of −2 ± 6°, indicating the stellar spin axis to be well-aligned with the orbit of the planet. We furthermore find evidence for transit timing variations suggesting the presence of an additional third body in the system. Conclusions. Together with the low orbital eccentricity, the good alignment suggests that this warm giant planet has not undergone high-eccentricity migration.

In this work we compare three catalogues of cosmological filaments identified in the Sloan Digital Sky Survey by means of different algorithms by Tempel et al., Pereyra et al., and Mart\'inez et al. We analyse how different identification techniques determine differences in the filament statistical properties: length, elongation, redshift distribution, and abundance. We find that the statistical properties of the filaments strongly depend on the identification algorithm. We use a volume limited sample of galaxies to characterise other properties of filaments such as: galaxy overdensity, luminosity function of galaxies, mean galaxy luminosity, filament luminosity, and the overdensity profile of galaxies around filaments. In general, we find that these properties primarily depended on filament length. Shorter filaments have larger overdensities, are more populated by red galaxies, and have better defined galaxy overdensity profiles, than longer filaments. Concluding that galaxies belonging to filaments have characteristic signatures depending on the identification algorithm used., Comment: 14 pages, 17 figures. Accepted for publication in MNRAS

U Sunčevom sustavu, osim Sunca i planeta, do danas je otkriveno gotovo milijun malih tijela Sunčevog sustava. Zbog njihovih malih dimenzija, oni spadaju u objekte čije istraživanje često zahtijeva teleskope velikih promjera ili primjenu suvremenih opažačkih metoda. Jedna od suvremenih opažačkih metoda određivanja fizikalnih karakteristika malih tijela Sunčevog sustava, koja dozvoljava razlučivosti veće od bilo koje druge zemaljske metode, jest metoda zvjezdanih okultacija. Mala tijela po sastavu i orbitalnim parametrima možemo klasificirati u asteroide i komete. Međutim, među asteroidima se pojavljuje malobrojna skupina objekata koji pokazuju aktivnosti slične kometskim. U doktorskom radu istražena je mikroaktivnost malog tijela 95P/(2060) Chiron. Zbog nedavne indikacije da bi Chiron mogao posjedovati prstenove, njegov mehanizam gubitka mase može biti objašnjen udarima krhotina iz Chironove orbite koje padaju na njegovu površinu. Opažanja su prikupljana na Španjolskoj zvjezdarnici Calar Alto, a za analizu su uglavnom korištene fotometrijske metode. Određivanjem Chironove rotacijske krivulje sjaja i njegove apsolutne zvjezdane veličine, potvrđena je pretpostavka da Chiron posjeduje prstenove. Kao primjer primjene metode zvjezdanih okultacija u svrhu istraživanja fizičkih karakteristika malih tijela Sunčevog sustava, opisano je određivanje veličine, oblika, albeda i gustoće patuljastog planeta Haumea, gornje granice Haumeine atmosfere, te otkriće i karakterizacija prstenova oko glavnog tijela Haumee. U svrhu poboljšanja vremenske razlučivosti opažanja zvjezdanih okultacija s malim tijelima, istražena je i opisana mogućnost primjene atmosferskih Čerenkovljevih teleskopa MAGIC. Njihovi veliki promjeri i osjetljivi fotomultiplikatorski detektori s visokim frekvencijama uzorkovanja, osim za unapređenje razlučivosti u određivanju fizičkih karakteristika malih tijela Sunčevog sustava, mogu biti korišteni za izravna mjerenja promjera zvijezda. U doktorskom radu opisana je metoda određivanja zvjezdanih promjera pomoću detekcije Fresnelovih difrakcijskih uzoraka, koji se mogu opaziti tijekom zvjezdanih okultacija. Detaljno je modeliran signal kakav bi bio opažen teleskopima MAGIC, uzevši u obzir karakteristike teleskopa i osjetljivost detektora. Kroz opažačke prijedloge ostvareno je teleskopsko vrijeme za opažanje zvjezdanih okultacija s MAGIC teleskopima. Extended abstract - Besides the Sun and the planets, our Solar System contains nearly 1 million discovered small Solar System bodies. Due to their small size, they belong to objects whose research often requires large-sized telescopes or the application of modern observation methods. One of today’s modern observational methods used for determining the physical characteristics of the small Solar System bodies, allowing several orders of magnitude better resolutions than any other Earth-based method, is the stellar occultations method. By composition and orbital parameters, small Solar System bodies can be classified into asteroids and comets. Nevertheless, there is a group of asteroid-like objects that show cometlike activities. This doctoral thesis consists of 3 parts. In part one, the observed micro activity of the small Solar System body 95P/(2060) Chiron was investigated. In part two, as an extensive example of the application of the stellar occultation method to investigate the physical characteristics of small Solar System bodies, the determination of the dwarf planet’s Haumea size, shape, albedo, and density was described. In part three, in order to improve the temporal resolution of observations of stellar occultations with small bodies, the potential of using the atmospheric Cherenkov telescopes MAGIC for observing stellar occultations was investigated. Activity of 95P/(2060) Chiron The minor planet 95P/(2060) Chiron belongs to the asteroid group of centaurs, which according to dynamic parameters belongs to asteroids. Chiron has an orbit far away from the Sun, in which sublimation of water ice is not considered as a possible cause for triggering mass loss mechanisms. The expected rate of collisions among small bodies in the region of centaurs is not expected to be high. Regardless of that, since its discovery, Chiron has repeatedly shown indications of cometary activity (Kowal et al. 1979; Tholen et al. 1988; Meech Belton 1990). In 2015, Ortiz et al. (2015) found indications that (2060) Chiron possesses rings. Motivated by these findings, additional observations and interpretations of the cause of its activity were made and described in this doctoral thesis (and published in Cikota et al., 2018). Observations were carried out in three different observation campaigns between 2014 and 2016, using three different instruments located at the Calar Alto Observatory (CAHA) in Almeria, Spain - 3.5 m MOSCA, 1.23 m DLR-MKIII and 2.2 m CAFOS. From the collected observations, amplitudes of Chiron’s rotational light curves and measurements of Chiron’s absolute magnitudes were determined. The measured amplitudes are consistent with the model proposed by Ortiz et al. (2015) which is taking into account both, Chiron’s triangular ellipsoid-like shape and the light contribution of rings around Chiron. Although the frequency of collisions among small bodies in the centaur region is very low, iv due to the recent indication that Chiron possesses rings, and assuming that there is debris orbiting around Chiron, it is well possible that some of this debris may be continually falling and impacting on its surface, producing outbursts and forming a bound or quasi-bound coma. Consequently, a dust release mechanism triggered by impacts should not be excluded as a possible cause for its activity. To study this hypothesis, the scatter in Chiron’s photometric data was compared to the scatter of comparison stars of similar brightness as Chiron. The scatter of Chiron’s photometric measurements for the observations carried out on July 23 and 24, 2014, with the DLR-MKIII 1.23 m CAHA telescope was found to be 0.027 mag, while the comparison star’s scatter is 0.014 mag. During the photometric campaign in 2015, containing data collected with CAFOS 2.2 m CAHA telescope on September 11 and September 13, the scatter of Chiron’s photometric measurements was determined to be 0.029 mag, while the comparison star’s scatter values were 0.018 mag. The noticeable difference between the comparison star’s and Chiron’s photometric scatter supports our hypothesis of continuous micro activity on Chiron. That mechanism could also be a plausible explanation for impulsive brightening on a timescale of hours that have been observed by Luu Jewitt (1990). We hypothesize that some activity outbursts on regular comets could also be triggered by collisions, either with debris orbiting them or with meteoroids. Additionally, the data collected with the CAFOS 2.2 m CAHA telescope over 3 nights between September 11 and September 14, 2015, was used to search for comet-like activity signs like coma or tail. The data was combined to a false-color image of Chiron that contains 95 integrations of 300 s each, resulting in a total integration time of 28500 s (475 min). The combined image of Chiron shows that the coma itself is not detectable, but a very faint asymmetric shape with a measured position angle of ∼ 87◦ was observed. The feature can be explained by a ∼5 arcsec long comet-like tail, of a determined surface brightness of 25.3 mag(R)/arcsec2. Determination of the dwarf planet Haumea’s physical characteristics - Five dwarf planets are currently known in our Solar system. (1) Ceres is the closest dwarf planet to us, and the only dwarf planet orbiting in the inner part of the Solar system, within the main belt of asteroids. Four dwarf planets - (134340) Pluto, (136199) Eris, (136108) Haumea, and (136472) Makemake, are members of the Kuiper belt, located in the outer part of the Solar system beyond Neptune’s orbit. Due to the large distances of dwarf planets in the outer Solar system, indirect observation methods are necessary to accurately determine their physical characteristics. Among trans-Neptunian objects, the dwarf planet Haumea stands out in its elongated shape and extremely short rotation period (Brown et al. 2005; Rabinowitz et al. 2006; Brown et al. 2007). Unlike other dwarf planets (Sicardy et al. 2011; Ortiz et al. 2012; Stern et al. v 2015), Haumea’s physical characteristics were not precisely determined. In this doctoral thesis, the determination of Haumea’s size, shape, albedo, and density was described, as well as the discovery and characterization of its rings (published in Ortiz et al. 2017). On January 21, 2017, a stellar occultation of the dwarf planet Haumea was observed. The occulted star URAT1 533-182543 with its apparent brightness of 𝑚𝑅 = 17.6 mag made it observable already for small- and mid-sized telescopes. Therefore, the occultation event was observed from many locations and resulted in 12 positive detections from 10 different sites across Europe. From the collected sequences of CCD images, photometric measurements of the synthetic aperture were performed. In the case of data collected from the Črni Vrh Observatory by the drift method, a special procedure of photometric analysis was applied to the stellar trail. By fitting a square well model to the collected photometric measurements, the times of the star’s disappearance and reappearance were determined, and occultation chords were generated for each observation location. To the chords in the projected plane, an elliptical limb was fitted by minimizing a 𝜒2 function. By that, the apparent edge of the shape of the ellipse, which represents the outline of Haumea’s shadow, was determined. The determined parameters of the major and minor axis of the ellipse are 1 704 ± 4 km and 1 138 ± 26 km respectively. The position angle of the minor axis is -76.3◦ ± 1.2◦. A search for an atmosphere was performed and the upper value of Haumea’s atmospheric pressure was determined by using the best available data set collected by the Asiago Observatory. From Haumea’s mass, and assuming that the body is in hydrostatic equilibrium, an average surface gravity of 0.39 ms−2 was determined. By comparing a modelled occultation light curve with the observed light curve, the upper value of Haumea’s pure isothermal global atmosphere of 𝑁2 in thermal equilibrium can be determined. Assuming a surface temperature of 40 K, we find a 1 𝜎 upper limit for 𝑝surface(𝑁2) = 3 nbar, and a 3 𝜎 upper limit for 𝑝surface(𝑁2) = 15 nbar. In addition to the main occultation, there are brief dimmings prior to and after the main event. These dips are consistently explained by a narrow and dense ring around Haumea that absorbed about 50% of the incoming stellar flux. A distinct cross-sectional profile of the rings collected in an observation with the 1 m telescope of the Konkoly Observatory reveals a radial ring width of 𝑊ring ≈ 74 km at the occultation ingress and 𝑊ring ≈ 44 km at the occultation egress, with corresponding apparent transparency of p’ = 0.55 and p’ = 0.56. The locations of twelve detected secondary events, projected in the sky plane, allow the retrieval of the full ring orbit, assuming an apparent elliptical shape, and using the same approach as used for fitting Haumea’s limb. The parameters of the elliptical fit to the rings are 𝑎0 ring = 2287+75 −45 km for the apparent semimajor axis, and 𝑏0 ring = 541 ± 23 km for a semiminor axis. The position angle of the minor vi axis is 𝑃ring = -74.3◦ ± 1.3◦. Assuming the rings are circular, it implies a radius of the ring of 𝑟ring = 2287+75 −45 km and an inclination angle of 𝐵ring = 13,8◦ ± 0.5◦. The circular ring assumption is supported by the fact that the center of the ring ellipse coincides with the order of uncertainty with the center of the limb of Haumea’s main body. The position angle of the ring minor axis 𝑃ring = -74.3◦ ±1.3◦ coincides with that of the limb minor axis 𝑃limb = -76.3◦ ± 1.2◦, which is another strong argument that we are observing a ring that settled into Haumea’s equatorial plane. Furthermore, it was found that the radius of the rings coincides with the area where 3:1 spin-orbit resonances are expected. From the determined parameters of Haumea’s limb, a three-dimensional shape and density of Haumea were determined. The obtained parameters of the triaxial ellipsoid a × b × c are (1 161 ± 30) km × (852 ± 2) km × (513 ± 16) km. The mean value of the Haumea density, determined through the parameters of the triangular ellipsoid, and the mass determined by the orbital period of the Hi’iake satellite, is 1 885 ± 80 kg m−3. The geometric albedo of Haumea determined by our observations is 0.51, which is significantly smaller than the value of 0.804, as available in the most recent literature (Fornasier et al. 2013). Application of the atmospheric Cherenkov telescopes MAGIC for observing stellar occultations - In order to accurately determine the physical characteristics of small bodies by using the occultation method, a high temporal resolution of the detector is required. In order to improve the observational methods of stellar occultations, the use of the MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescopes was considered. With its sensitive central pixel, the MAGIC-II telescope has shown to be an excellent instrument for detecting millisecond flashes in the visible spectra. Compared to any other optical telescope used for observing stellar occultations, its central pixel with a temporal resolution of 10 kHz, combined with a large 17 m aperture, the MAGIC-II telescope enables reaching two orders higher resolutions. However, some of its limiting characteristics are the inability to control the sampling frequency, sensitivity only in the visible spectrum between 300 and 400 nm, and a low angular resolution (due to physically large pixels) responsible for a limitation in the apparent brightness of m = 13.5 ± 0.6 mag. In addition to determining the physical characteristics of small bodies, using the stellar occultation method enables us to determine the angular sizes of the occulted stars. Since stars are not point sources (they have a finite angular diameter), during the occultation of a stellar disk, its light curve does not show a sharp brightness drop but describes a Fresnel interference pattern whose details depend on the angular diameter of the occulted star. High sampling rates make it possible to record these interference patterns. Therefore, the high temporal resolution vii of the detector is the key for direct measurements of stellar radii. In this doctoral thesis, the method of determining stellar radii by observing Fresnel diffraction patterns that can be detected during stellar occultations is described. Models of the expected signal were performed, taking into account the characteristics of the MAGIC telescopes and the sensitivity of its detectors. Through observational proposals, telescope time was granted and first observations of stellar occultations with the MAGIC telescopes were acquired. Additionally, the effects of limb darkening of stellar disks were investigated. It was found that diffraction patterns formed by occultations of large disks with angular diameters of 0.7 mas and high limb darkening factors of u = 1.0 deviate in intensity up to approximately 5% from diffraction patterns of homogeneously illuminated stellar disks (u = 0.0). For stellar disks of smaller diameters or smaller limb darkening factors, the intensity deviations are smaller. These deviations in the intensity of diffraction patterns are reflected in the determination of the angular diameters of stellar disks. It was found that the angular radius of a homogeneously illuminated stellar disk, compared to a disk with a limb darkening factor of u = 1.0 taken into account, deviates by approximately 12.4%. Taking the limb darkening factors into account contributes to the accuracy of measurements of the angular diameters of stellar disks, but to achieve this accuracy, photometric measurements with uncertainties below 5% are required. Historically, almost all measurements of the stellar radii smaller than ∼1 arc millisecond have been performed by interferometric measurements. Measurements of stellar radii by observing occultations with asteroids allow reaching angular resolutions up to 0.1 milliarcseconds, which is at least a factor of two larger than the one available through interferometric measurements, and a factor of 10 larger than what can be achieved by observing lunar occultations. Therefore, the asteroid occultation method is extremely useful for measuring the angular diameters of stars below 1 milliarcsecond. In the period from December 2017 to February 2020, a total of 6 occultation observations with the MAGIC-II telescope were scheduled. Four observations were not successfully acquired due to bad weather or technical reasons. Two occultation events, those by the small bodies (83) Beatrix and (28) Bellona, were successfully acquired but resulted in a negative detection. Although the occultation events of (83) Beatrix and (28) Bellona occurred over sufficiently bright sources, and their probability of observation was estimated at 99%, the negative detections can be explained by a too small brightness drops, ∼1.5 mag for the (83) Beatrix event (2.5 𝜎), and ∼0.9 mag for the (28) Bellona event (1.5 𝜎). Based on the analysis presented in this thesis, we expect that any event with a brightness drop larger than 1.8-3.0 mag (3-5 𝜎 above background noise) should be detected. Therefore, the observation campaign of occultations on MAGIC telescopes will be continued in the future.

We report 18 dust continuum detections ($\geq 3.3\sigma$) at $\sim88{\rm \mu m}$ and $158{\rm \mu m}$ out of 49 ultraviolet(UV)-bright galaxies ($M_{\rm UV} < -21.3$ mag) at $z>6.5$, observed by the Cycle-7 ALMA Large Program, REBELS and its pilot programs. This has more than tripled the number of dust continuum detections known at $z>6.5$. Out of these 18 detections, 12 are reported for the first time as part of REBELS. In addition, 15 of the dust continuum detected galaxies also show a [CII]$_{\rm 158{\rm \mu m}}$ emission line, providing us with accurate redshifts. We anticipate more line emission detections from six targets (including three continuum detected targets) where observations are still ongoing. The dust continuum detected sources in our sample tend to have a redder UV spectral slope than the ones without a dust continuum detection. We estimate that all of the sources have an infrared (IR) luminosity ($L_{\rm IR}$) in a range of $3-8 \times 10^{11} L_\odot$, except for one with $L_{\rm IR} = 1.5^{+0.8}_{-0.5} \times 10^{12}\,L_{\odot}$. Their fraction of obscured star formation is significant at $\gtrsim 50\%$. Some of the dust continuum detected galaxies show spatial offsets ($\sim 0.5-1.5''$) between the rest-UV and far-IR emission peaks. These separations appear to have an increasing trend against an indicator that suggests spatially decoupled phases of obscured and unobscured star formation. REBELS offers the best available statistical constraints on obscured star formation in UV-bright, massive galaxies at $z > 6.5$., Comment: 17 pages, 9 figures, 4 tables, Accepted for publication in MNRAS

We investigate the role of secondary electron and ion emission from impact of gas molecules on the Cassini Langmuir Probe (RPWS-LP, or LP) measurements in the ionosphere of Saturn. We add a model of the emission currents, based on laboratory measurements and data from comet 1P/Halley, to the equations used to derive plasma parameters from LP bias voltage sweeps. Reanalysing several hundred sweeps from the Cassini Grand Finale orbits, we find reasonable explanations for three open conundrums from previous LP studies of the Saturn ionosphere. We find an explanation for the observed positive charging of the Cassini spacecraft, the possibly overestimated ionospheric electron temperatures, and the excess ion current reported. For the sweeps analysed in detail, we do not find (indirect or direct) evidence of dust having a significant charge-carrying role in Saturn's ionosphere. We also produce an estimate of H2O number density from the last six revolutions of Cassini through Saturn's ionosphere in higher detail than reported by the Ion and Neutral Mass Spectrometer (INMS). Our analysis reveals an ionosphere that is highly structured in latitude across all six final revolutions, with mixing ratios varying with two orders of magnitude in latitude and one order of magnitude between revolutions and altitude. The result is generally consistent with an empirical photochemistry model balancing the production of H+ ions with the H+ loss through charge transfer with e.g., H2O, CH4 and CO2, for which water vapour appears as the likeliest dominant source of the signal in terms of yield and concentration., Comment: 11 pages, 7 figures

Full list of authors: Gilmore, G.; Randich, S.; Worley, C. C.; Hourihane, A.; Gonneau, A.; Sacco, G. G.; Lewis, J. R.; Magrini, L.; Francois, P.; Jeffries, R. D.; Koposov, S. E.; Bragaglia, A.; Alfaro, E. J.; Allende Prieto, C.; Blomme, R.; Korn, A. J.; Lanzafame, A. C.; Pancino, E.; Recio-Blanco, A.; Smiljanic, R.; Van Eck, S.; Zwitter, T.; Bensby, T.; Flaccomio, E.; Irwin, M. J.; Franciosini, E.; Morbidelli, L.; Damiani, F.; Bonito, R.; Friel, E. D.; Vink, J. S.; Prisinzano, L.; Abbas, U.; Hatzidimitriou, D.; Held, E., V; Jordi, C.; Paunzen, E.; Spagna, A.; Jackson, R. J.; Maiz Apellaniz, J.; Asplund, M.; Bonifacio, P.; Feltzing, S.; Binney, J.; Drew, J.; Ferguson, A. M. N.; Micela, G.; Negueruela, I; Prusti, T.; Rix, H-W; Vallenari, A.; Bergemann, M.; Casey, A. R.; de Laverny, P.; Frasca, A.; Hill, V; Lind, K.; Sbordone, L.; Sousa, S. G.; Adibekyan, V; Caffau, E.; Daflon, S.; Feuillet, D. K.; Gebran, M.; Gonzalez Hernandez, J., I; Guiglion, G.; Herrero, A.; Lobel, A.; Montes, D.; Morel, T.; Ruchti, G.; Soubiran, C.; Tabernero, H. M.; Tautvaisiene, G.; Traven, G.; Valentini, M.; Van der Swaelmen, M.; Villanova, S.; Vazquez, C. Viscasillas; Bayo, A.; Biazzo, K.; Carraro, G.; Edvardsson, B.; Heiter, U.; Jofre, P.; Marconi, G.; Martayan, C.; Masseron, T.; Monaco, L.; Walton, N. A.; Zaggia, S.; Borsen-Koch, V. Aguirre; Alves, J.; Balaguer-Nunez, L.; Barklem, P. S.; Barrado, D.; Bellazzini, M.; Berlanas, S. R.; Binks, A. S.; Bressan, A.; Capuzzo-Dolcetta, R.; Casagrande, L.; Casamiquela, L.; Collins, R. S.; D'Orazi, V; Dantas, M. L. L.; Debattista, V. P.; Delgado-Mena, E.; Di Marcantonio, P.; Drazdauskas, A.; Evans, N. W.; Famaey, B.; Franchini, M.; Fremat, Y.; Fu, X.; Geisler, D.; Gerhard, O.; Solares, E. A. Gonzalez; Grebel, E. K.; Gutierrez Albarran, M. L.; Jimenez-Esteban, F.; Jonsson, H.; Khachaturyants, T.; Kordopatis, G.; Kos, J.; Lagarde, N.; Ludwig, H-G; Mahy, L.; Mapelli, M.; Marfil, E.; Martell, S. L.; Messina, S.; Miglio, A.; Minchev, I; Moitinho, A.; Montalban, J.; Monteiro, M. J. P. F. G.; Morossi, C.; Mowlavi, N.; Mucciarelli, A.; Murphy, D. N. A.; Nardetto, N.; Ortolani, S.; Paletou, F.; Palous, J.; Pickering, J. C.; Quirrenbach, A.; Fiorentin, P. Re; Read, J., I; Romano, D.; Ryde, N.; Sanna, N.; Santos, W.; Seabroke, G. M.; Spina, L.; Steinmetz, M.; Stonkute, E.; Sutorius, E.; Thevenin, F.; Tosi, M.; Tsantaki, M.; Wright, N.; Wyse, R. F. G.; Zoccali, M.; Zorec, J.; Zucker, D. B.-- This is an Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., Context. The Gaia-ESO Public Spectroscopic Survey is an ambitious project designed to obtain astrophysical parameters and elemental abundances for 100 000 stars, including large representative samples of the stellar populations in the Galaxy, and a well-defined sample of 60 (plus 20 archive) open clusters. We provide internally consistent results calibrated on benchmark stars and star clusters, extending across a very wide range of abundances and ages. This provides a legacy data set of intrinsic value, and equally a large wide-ranging dataset that is of value for the homogenisation of other and future stellar surveys and Gaia's astrophysical parameters. Aims. This article provides an overview of the survey methodology, the scientific aims, and the implementation, including a description of the data processing for the GIRAFFE spectra. A companion paper introduces the survey results. Methods. Gaia-ESO aspires to quantify both random and systematic contributions to measurement uncertainties. Thus, all available spectroscopic analysis techniques are utilised, each spectrum being analysed by up to several different analysis pipelines, with considerable effort being made to homogenise and calibrate the resulting parameters. We describe here the sequence of activities up to delivery of processed data products to the ESO Science Archive Facility for open use. Results. The Gaia-ESO Survey obtained 202 000 spectra of 115 000 stars using 340 allocated VLT nights between December 2011 and January 2018 from GIRAFFE and UVES. © G. Gilmore et al. 2022. Conclusions. The full consistently reduced final data set of spectra was released through the ESO Science Archive Facility in late 2020, with the full astrophysical parameters sets following in 2022. A companion article reviews the survey implementation, scientific highlights, the open cluster survey, and data products., Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 188.B-3002. These data products have been processed by the Cambridge Astronomy Survey Unit (CASU) at the Institute of Astronomy, University of Cambridge, and by the FLAMES/UVES reduction team at INAF/Osservatorio Astrofisico di Arcetri. Public access to the data products is via the ESO SAF, and the Gaia-ESO Survey Data Archive, prepared and hosted by the Wide Field Astronomy Unit, Institute for Astronomy, University of Edinburgh, which is funded by the UK Science and Technology Facilities Council. This work was partly supported by the European Union FP7 programme through ERC grant number 320360 and by the Leverhulme Trust through grant RPG-2012-541. We acknowledge the support from INAF and Ministero dell’ Istruzione, dell’ Università’ e della Ricerca (MIUR) in the form of the grant “Premiale VLT 2012”. The project presented here benefited in development from discussions held during the Gaia-ESO workshops and conferences supported by the ESF (European Science Foundation) through the GREAT Research Network Programme. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. R.S. acknowledges support from the National Science Centre, Poland (2014/15/B/ST9/03981). This work was partly supported by the INAF grant for mainstream projects: “Enhancing the legacy of the Gaia-ESO Survey for open cluster science”. F.J.E. acknowledges financial support from the Spanish MINECO/FEDER through the grant AYA2017-84089 and MDM-2017-0737 at Centro de Astrobiología (CSIC-INTA), Unidad de Excelencia María de Maeztu, and from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement no. 824064 through the ESCAPE – the European Science Cluster of Astronomy and Particle Physics ESFRI Research Infrastructures project. T.B. was funded by the “The New Milky Way” project grant from the Knut and Alice Wallenberg Foundation. S.R.B. acknowledges support by the Spanish Government under grants AYA2015-68012-C2-2-P and PGC2018-093741-B-C21/C22 (MICIU/AEI/FEDER, UE). W.J.S. acknowledges CAPES for a PhD studentship. J.M.A. acknowledges support from the Spanish Government Ministerio de Ciencia e Innovación through grants AYA2013-40611-P, AYA2016-75931-C2-2-P, and PGC2018-095049-B-C22. T.M. and others from STAR institute, Liege, Belgium are grateful to Belgian F.R.S.-FNRS for support, and are also indebted for an ESA/PRODEX Belspo contract related to the Gaia Data Processing and Analysis Consortium and for support through an ARC grant for Concerted Research Actions financed by the Federation Wallonie-Brussels.. This research has been partially supported by the following grants: MIUR Premiale “Gaia-ESO survey” (PI S. Randich), MIUR Premiale “MiTiC: Mining the Cosmos” (PI B. Garilli), the ASI-INAF contract 2014-049-R.O: “Realizzazione attività tecniche/scientifiche presso ASDC” (PI Angelo Antonelli), Fondazione Cassa di Risparmio di Firenze, progetto: “Know the star, know the planet” (PI E. Pancino), and Progetto Main Stream INAF: “Chemo-dynamics of globular clusters: the Gaia revolution” (PI E. Pancino). V.A. acknowledges the support from Fundação para a Ciência e Tecnologia (FCT) through Investigador FCT contract nr. IF/00650/2015/CP1273/CT0001. A.J.K. acknowledges support by the Swedish National Space Agency (SNSA). A.B. acknowledges support by ANID, – Millennium Science Initiative Program – NCN19_171, and FONDECYT regular 1190748. E.M. acknowledges financial support from the Spanish State Research Agency (AEI) through project MDM-2017-0737 Unidad de Excelencia “María de Maeztu” – Centro de Astrobiología (CSIC-INTA). T.Z. acknowledges financial support of the Slovenian Research Agency (research core funding no. P1-0188) and the European Space Agency (Prodex Experiment Arrangement No. C4000127986). P.J. acknowledges support FONDECYT Regular 1200703. The work of I.N. is partially supported by the Spanish Government Ministerio de Ciencia, Innovación y Universidades under grant PGC2018-093741-B-C21 (MICIU/AEI/FEDER, UE). Funding for this work has been provided by the ARC Future Fellowship FT160100402. C.A.P. acknowledges financial support from the Spanish Government through research grants MINECO AYA 2014-56359-P, MINECO AYA2017-86389-P, and MICINN PID2020-117493GB-I00. S.F. was supported by the grants 2011-5042 and 2016-03412 from the Swedish Research Council and the project grant “The New Milky Way” from the Knut and Alice Wallenberg Foundation. C.A.S.U. is supported through STFC grants: ST/H004157/1, ST/J00541X/1, ST/M007626/1, ST/N005805/1, ST/T003081/1. Work reported here benefited from support through the GREAT-ITN FP7 project Grant agreement ID: 264895. D.K.F. acknowledges funds from the Alexander von Humboldt Foundation in the framework of the Sofja Kovalevskaja Award endowed by the Federal Ministry of Education and Research and the grant 2016-03412 from the Swedish Research Council. A.H. acknowledges support from the Spanish Government Ministerio de Ciencia e Innovación and ERD Funds through grants PGC-2018-091 3741-B-C22 and CEX2019-000920-S. X.F. acknowledges the support of China Postdoctoral Science Foundation 2020M670023. M.L.L.D. acknowledges the Polish NCN grant number 2019/34/E/ST9/00133. Part of this work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project-ID 138713538 – SFB 881 (“The Milky Way System”, subproject A09). M.Z. acknowledges support from the National Agency for Research and Development (ANID) grants: FONDECYT Regular 1191505, Millennium Institute of Astrophysics ICN12-009, BASAL Center for Astrophysics and Associated Technologies AFB-170002. R.B. acknowledges support from the project PRIN-INAF 2019 “Spectroscopically Tracing the Disk Dispersal Evolution”. H.M.T. acknowledges financial support from the Agencia Estatal de Investigación of the Ministerio de Ciencia, Innovación y Universidades through projects PID2019-109522GB-C51,54/AEI/10.13039/501100011033, and the Centre of Excellence “María de Maeztu” award to Centro de Astrobiología (MDM-2017-0737). J.I.G.H. acknowledges financial support from the Spanish Ministry of Science and Innovation (MICINN) project AYA2017-86389-P, and also from the Spanish MICINN under 2013 Ramѳn y Cajal program RYC-2013-14875. V.P.D. is supported by STFC Consolidated grant ST/R000786/1. N.L. acknowledges financial support from “Programme National de Physique Stellaire” (PNPS) and the “Programme National Cosmology et Galaxies (PNCG)” of CNRS/INSU, France. A.R.C. is supported in part by the Australian Research Council through a Discovery Early Career Researcher Award (DE190100656). Parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. P.S.B. is supported by the Swedish Research Council through individual project grants with contract Nos. 2016-03765 and 2020-03404. A.M. acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 772293 – project ASTEROCHRONOMETRY). J.P. was supported by the project RVO: 67985815. E.D.M. acknowledges the support from FCT through the research grants UIDB/04434/2020 & UIDP/04434/2020 and through Investigador FCT contract IF/00849/2015/CP1273/CT0003. This work was (partially) supported by the Spanish Ministry of Science, Innovation and University (MICIU/FEDER, UE) through grant RTI2018-095076-B-C21, and the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia 'María de Maeztu’) through grant CEX2019-000918-M. S.L.M. acknowledges the support of the UNSW Scientia Fellowship program and the Australian Research Council through Discovery Project grant DP180101791. GT acknowledges financial support of the Slovenian Research Agency (research core funding No. P1-0188) and the European Space Agency (Prodex Experiment Arrangement No. C4000127986). S.G.S acknowledges the support from FCT through Investigador FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). H.G.L. acknowledges financial support by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project-ID 138713538 – SFB 881 (“The Milky Way System”, subproject A04). This work was (partially) supported by the Spanish Ministry of Science, Innovation and University (MICIU/FEDER, UE) through grant RTI2018-095076-B-C21, and the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia ’María de Maeztu’) through grant CEX2019-000918-M. T.K. is supported by STFC Consolidated grant ST/R000786/1. M.V. acknowledges the support of the Deutsche Forschungsgemeinschaft (DFG, project number: 428473034). T.M. is supported by a grant from the Fondation ULB. We acknowledge financial support from the Universidad Complutense de Madrid (UCM) and by the Spanish Ministerio de Ciencia, Innovación y Universidades, Ministerio de Economía y Competitividad, from project AYA2016-79425-C3-1-P and PID2019-109522GB-C5[4]/AEI/10.13039/501100011033. U.H. acknowledges support from the Swedish National Space Agency (SNSA/Rymdstyrelsen). D.G. gratefully acknowledges support from the Chilean Centro de Excelencia en Astrofísica y Tecnologías Afines (CATA) BASAL grant AFB-170002. D.G. also acknowledges financial support from the Dirección de Investigación y Desarrollo de la Universidad de La Serena through the Programa de Incentivo a la Investigación de Académicos (PIA-DIDULS). A. Lobel acknowledges support in part by the Belgian Federal Science Policy Office under contract No. BR/143/A2/BRASS. We acknowledge financial support from the Universidad Complutense de Madrid (UCM) and by the Spanish Ministerio de Ciencia, Innovación y Universidades, Ministerio de Economía y Competitividad, from project AYA2016-79425-C3-1-P and PID2019-109522GB-C5[4]/AEI/10.13039/501100011033. A.M. acknowledges the support from the Portuguese Fundação para a Ciência e a Tecnologia (FCT) through the Portuguese Strategic Programme UID/FIS/00099/2019 for CENTRA. T.M. acknowledges financial support from the Spanish Ministry of Science and Innovation (MICINN) through the Spanish State Research Agency, under the Severo Ochoa Program 2020-2023 (CEX2019-000920-S). E.J.A. acknowledges funding from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de An- dalucía (SEV-2017-0709).

Full list of authors: Morgado, B. E.; Bruno, G.; Gomes-Junior, A. R.; Pagano, I; Sicardy, B.; Fortier, A.; Desmars, J.; Maxted, P. F. L.; Braga-Ribas, F.; Queloz, D.; Sousa, S. G.; Ortiz, J. L.; Brandeker, A.; Cameron, A. Collier; Pereira, C. L.; Floren, H. G.; Hara, N.; Souami, D.; Isaak, K. G.; Olofsson, G.; Santos-Sanz, P.; Wilson, T. G.; Broughton, J.; Alibert, Y.; Alonso, R.; Anglada, G.; Barczy, T.; Barrado, D.; Barros, S. C. C.; Baumjohann, W.; Beck, M.; Beck, T.; Benz, W.; Billot, N.; Bonfils, X.; Broeg, C.; Cabrera, J.; Charnoz, S.; Csizmadia, S.; Davies, M. B.; Deleuil, M.; Delrez, L.; Demangeon, O. D. S.; Demory, B. O.; Ehrenreich, D.; Erikson, A.; Fossati, L.; Fridlund, M.; Gandolfi, D.; Gillon, M.; Gudel, M.; Heng, K.; Hoyer, S.; Kiss, L. L.; Laskar, J.; des Etangs, A. Lecavelier; Lendl, M.; Lovis, C.; Magrin, D.; Marafatto, L.; Nascimbeni, V; Ottensamer, R.; Palle, E.; Peter, G.; Piazza, D.; Piotto, G.; Pollacco, D.; Ragazzoni, R.; Rando, N.; Ratti, F.; Rauer, H.; Reimers, C.; Ribas, I; Santos, N. C.; Scandariato, G.; Segransan, D.; Simon, A. E.; Smith, A. M. S.; Steller, M.; Szabo, G. M.; Thomas, N.; Udry, S.; Van Grootel, V.; Walton, N. A.; Westerdorff, K.--This is an Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., Context. Stellar occultation is a powerful technique that allows the determination of some physical parameters of the occulting object. The result depends on the photometric accuracy, the temporal resolution, and the number of chords obtained. Space telescopes can achieve high photometric accuracy as they are not affected by atmospheric scintillation. Aims. Using ESA’s CHEOPS space telescope, we observed a stellar occultation by the transneptunian object (50000) Quaoar. We compare the obtained chord with previous occultations by this object and determine its astrometry with sub-milliarcsecond precision. Also, we determine upper limits to the presence of a global methane atmosphere on the occulting body. Methods. We predicted and observed a stellar occultation by Quaoar using the CHEOPS space telescope. We measured the occultation light curve from this dataset and determined the dis- and reappearance of the star behind the occulting body. Furthermore, a ground-based telescope in Australia was used to constrain Quaoar’s limb. Combined with results from previous works, these measurements allowed us to obtain a precise position of Quaoar at the occultation time. Results. We present the results obtained from the first stellar occultation by a transneptunian object using a space telescope orbiting Earth; it was the occultation by Quaoar observed on 2020 June 11. We used the CHEOPS light curve to obtain a surface pressure upper limit of 85 nbar for the detection of a global methane atmosphere. Also, combining this observation with a ground-based observation, we fitted Quaoar’s limb to determine its astrometric position with an uncertainty below 1.0 mas. Conclusions. This observation is the first of its kind, and it shall be considered as a proof of concept of stellar occultation observations of transneptunian objects with space telescopes orbiting Earth. Moreover, it shows significant prospects for the James Webb Space Telescope. © B. Morgado et al. 2022, This work was carried out within the “Lucky Star” umbrella that agglomerates the efforts of the Paris, Granada and Rio teams, which is funded by the European Research Council under the European Community’s H2020 (ERC Grant Agreement No. 669416). CHEOPS is an ESA mission in partnership with Switzerland with important contributions to the payload and the ground segment from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden, and the United Kingdom. The CHEOPS Consortium would like to gratefully acknowledge the support received by all the agencies, offices, universities, and industries involved. Their flexibility and willingness to explore new approaches were essential to the success of this mission. This research made use of SORA, a python package for stellar occultations reduction and analysis, developed with the support of ERC Lucky Star and LIneA/Brazil, within the collaboration of Rio-Paris-Granada teams. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). This study was financed in part by the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo, CNPq grant 465376/2014-2). The following authors acknowledge the respective (i) CNPq grants: BEM 150612/2020-6; FB-R 314772/2020-0; (ii) CAPES/Cofecub grant: BEM 394/2016-05. (iii) FAPESP grants: ARGJr 2018/11239-8; GBr, VNa, IPa, GPi, RRa, and GSc acknowledge support from CHEOPS ASI-INAF agreement n. 2019-29-HH.0. ABr was supported by the SNSA. ACC acknowledges support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. KGI is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. ACC and TW acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. YA and MJH acknowledge the support of the Swiss National Fund under grant 200020_172746. We acknowledge support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, PGC2018-098153-B-C33, PGC2018-098153-B-C31, ESP2017-87676-C5-1-R, MDM-2017-0737 Unidad de Excelencia Maria de Maeztu-Centro de Astrobiologíca (INTA-CSIC), as well as the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract No. 4000124370. SCCB acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. XB, SC, DG, MF and JL acknowledge their role as ESA-appointed CHEOPS science team members. This project was supported by the CNES. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Liège through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. LD is an F.R.S.-FNRS Postdoctoral Researcher. This work was supported by FCT – Fundação para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalizacão by these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 and POCI-01-0145-FEDER- 032113, PTDC/FIS-AST/28953/2017 and POCI-01-0145-FEDER-028953, PTDC/FIS-AST/28987/2017 and POCI-01-0145-FEDER-028987, ODSD is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. PSS acknowledges financial support by the Spanish grant AYA-RTI2018-098657-J-I00 “LEO-SBNAF” (MCIU/AEI/FEDER, UE). PSS and JLO acknowledge financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709), they also acknowledge the financial support by the Spanish grants AYA-2017-84637-R and PID2020-112789GB-I00, and the Proyectos de Excelencia de la Junta de Andalucía 2012-FQM1776 and PY20-01309. BOD acknowledges support from the Swiss National Science Foundation (PP00P2-190080). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project FOUR ACES. grant agreement No 724427). It has also been carried out in the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). DE acknowledges financial support from the Swiss National Science Foundation for project 200021_200726. MF and CMP gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). DG gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 “Gaseous or rocky? Unveiling the nature of small worlds”. MG is an F.R.S.-FNRS Senior Research Associate. SH gratefully acknowledges CNES funding through the grant 837319. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip at Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche. ML acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. PM acknowledges support from STFC research grant number ST/M001040/1. This work was also partially supported by a grant from the Simons Foundation (PI Queloz, grant number 327127). IRI acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-B- C33, as well as the support of the Generalitat de Catalunya/CERCA programme. SGS acknowledges support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). GyMSz acknowledges the support of the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, a a PRODEX Experiment Agreement No. 4000137122, the Lendület LP2018-7/2021 grant of the Hungarian Academy of Science and the support of the city of Szombathely. VVG is an F.R.S-FNRS Research Associate. NAW acknowledges UKSA grant ST/R004838/1.

11 pags., 11 figs., 7 tabs., Context. The isomerism of molecules in the interstellar medium and the mechanisms behind it are essential questions in the chemistry of organic molecules in space. In the particular case of simple formic and thioformic acids, the low temperatures found in molecular clouds indicate that cis-trans isomerization in the gas-phase must be impeded. Reactions taking place on top of interstellar dust grains may explain the isomer interconversion at low temperatures. Aims. We studied the isomerization processes of formic and thioformic acid that are likely to take place on the surface of interstellar dust grains after being initiated by H abstraction reactions. Similarly, deuterium enrichment of the acids can occur by the same mechanism. Our objective is to shed light on both topics to expand our understanding of the key precursors of organic molecules in space. Methods. We determined the rate constants for the H abstraction reactions as well as the binding energies for the acids on water ice using ab initio calculations and the instanton method for calculating the rate constants, including quantum tunneling. In addition, we tested the viability of the deuteration of formic acid with tailored experiments and looked for it on the L1544 source. Results. For formic acid, there is a clear dependence of the H abstraction reactions on the isomer of the reactant, with rate constants at ~50 K that differ by five orders of magnitude. Correspondingly, we did not observe the trans-cis reaction in our experiments. In the case of thioformic acid, a very similar cis-trans reactivity is found for abstraction reactions at the thiol (-SH) group in contrast to a preferential reactivity that is found when abstractions take place at the -CH moiety. We found comparable binding energies for both isomers with average binding energies of around - 6200 and - 3100 K for formic and thioformic acid, respectively. Our binding energy calculations show that the reactions are precluded for specific orientations, affecting the overall isomerization rate. For H abstractions initiated by deuterium atoms, we found very similar trends, with kinetic isotope effects varying in most cases between 13 and 20. Conclusions. Our results support the cis-trans interconversion of cis-formic acid on dust grains, suggesting that such an acid should not withstand the conditions found on these objects. On the other hand, the trans isomer is very resilient. Both isomers of thioformic acid are much more reactive. A non-trivial chemistry is behind the apparent excess of its trans isomer that is found in cold molecular clouds and star-forming regions due to a subtle combination of preferential reactivity and binding with the surface. In light of our results, all the deuterated counterparts of thioformic acid are viable molecules to be present on the ISM. In contrast, only the trans isomer of deuterated formic acid is expected, for which we provide upper bounds of detection. Given the mechanisms presented in this paper, other mechanisms must be at play to explain the tiny fraction of cis-formic acid observed in interstellar cold environments, as well as the current trans-DCOOH and trans-HCOOD abundances in hot-corinos., Computer time was granted by the state of BadenWürttemberg through bwHPC and the German Research Foundation (DFG) through grant no. INST 40/467-1FUGG is greatly acknowledged. G.M. thanks the Alexander von Humboldt Foundation for a post-doctoral research grant. We thank the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for supporting this work by funding EXC 2075 - 390740016 under Germany’s Excellence Strategy. We acknowledge the support by the Stuttgart Center for Simulation Science (SimTech). I.J.-S. and J.G.d.l.C. have received partial support from the Spanish State Research Agency (AEI) through project numbers PID2019-105552RB-C41 and MDM-2017-0737 Unidad de Excelencia “María de Maeztu”- Centro de Astrobiología (CSIC-INTA). We also acknowledge support from the Spanish National Research Council (CSIC) through the i-Link project number LINKA20353. This work is also supported by JSPS KAKENHI grant Nos. JP21F21319, JP21H04501, JP21H05414, JP21K18639, and JP17H06087 This work also made use of ASAI ”Astrochemical Surveys At IRAM” (Lefloch et al. 2017).

We study the host galaxy properties of active galactic nuclei (AGN) that have been detected in X-rays in the nearby Universe (z, Lazaros Koutoulidis (L.K.) acknowledges support from the State Scholarship Foundation (IKY). G. M. acknowledges support by the Agencia Estatal de Investigación, Unidad de Excelencia María de Maeztu, ref. MDM-2017-0765. I. G. and E. P. acknowledge financial support by the European Union’s Horizon 2020 programme “XMM2ATHENA” under grant agreement No 101004168. The research leading to these results has received funding from the European Union’s Horizon 2020 programme under the AHEAD2020 project (grant agreement n. 871158).

Full list of authors: Borlaff, A. S.; Gómez-Alvarez, P.; Altieri, B.; Marcum, P. M.; Vavrek, R.; Laureijs, R.; Kohley, R.; Buitrago, F.; Cuillandre, J. -C.; Duc, P. -A.; Gaspar Venancio, L. M.; Amara, A.; Andreon, S.; Auricchio, N.; Azzollini, R.; Baccigalupi, C.; Balaguera-Antolínez, A.; Baldi, M.; Bardelli, S.; Bender, R.; Biviano, A.; Bodendorf, C.; Bonino, D.; Bozzo, E.; Branchini, E.; Brescia, M.; Brinchmann, J.; Burigana, C.; Cabanac, R.; Camera, S.; Candini, G. P.; Capobianco, V.; Cappi, A.; Carbone, C.; Carretero, J.; Carvalho, C. S.; Casas, S.; Castander, F. J.; Castellano, M.; Castignani, G.; Cavuoti, S.; Cimatti, A.; Cledassou, R.; Colodro-Conde, C.; Congedo, G.; Conselice, C. J.; Conversi, L.; Copin, Y.; Corcione, L.; Coupon, J.; Courtois, H. M.; Cropper, M.; Da Silva, A.; Degaudenzi, H.; Di Ferdinando, D.; Douspis, M.; Dubath, F.; Duncan, C. A. J.; Dupac, X.; Dusini, S.; Ealet, A.; Fabricius, M.; Farina, M. ; Farrens, S.; Ferreira, P. G.; Ferriol, S.; Finelli, F.; Flose-Reimberg, P.; Fosalba, P.; Frailis, M.; Franceschi, E.; Fumana, M.; Galeotta, S.; Ganga, K.; Garilli, B.; Gillis, B.; Giocoli, C.; Gozaliasl, G.; Graciá-Carpio, J.; Grazian, A.; Grupp, F.; Haugan, S. V. H.; Holmes, W.; Hormuth, F.; Jahnke, K.; Keihanen, E.; Kermiche, S.; Kiessling, A.; Kilbinger, M.; Kirkpatrick, C. C.; Kitching, T.; Knapen, J. H.; Kubik, B.; Kümmel, M.; Kunz, M.; Kurki-Suonio, H.; Liebing, P.; Ligori, S.; Lilje, P. B.; Lindholm, V.; Lloro, I.; Mainetti, G.; Maino, D.; Mansutti, O.; Marggraf, O.; Markovic, K.; Martinelli, M.; Martinet, N.; Martínez-Delgado, D.; Marulli, F.; Massey, R.; Maturi, M.; Maurogordato, S.; Medinaceli, E.; Mei, S.; Meneghetti, M.; Merlin, E.; Metcalf, R. B.; Meylan, G.; Moresco, M.; Morgante, G.; Moscardini, L.; Munari, E.; Nakajima, R.; Neissner, C.; Niemi, S. M.; Nightingale, J. W.; Nucita, A.; Padilla, C.; Paltani, S.; Pasian, F.; Patrizii, L.; Pedersen, K.; Percival, W. J.; Pettorino, V.; Pires, S.; Poncet, M.; Popa, L.; Potter, D.; Pozzetti, L.; Raison, F.; Rebolo, R.; Renzi, A.; Rhodes, J.; Riccio, G.; Romelli, E.; Roncarelli, M.; Rosset, C.; Rossetti, E.; Saglia, R.; Sánchez, A. G.; Sapone, D.; Sauvage, M.; Schneider, P.; Scottez, V.; Secroun, A.; Seidel, G.; Serrano, S.; Sirignano, C.; Sirri, G.; Skottfelt, J.; Stanco, L.; Starck, J. L.; Sureau, F.; Tallada-Crespí, P.; Taylor, A. N.; Tenti, M.; Tereno, I.; Teyssier, R.; Toledo-Moreo, R.; Torradeflot, F.; Tutusaus, I.; Valentijn, E. A.; Valenziano, L.; Valiviita, J.; Vassallo, T.; Viel, M.; Wang, Y.; Weller, J.; Whittaker, L.; Zacchei, A.; Zamorani, G.; Zucca, E.; Euclid Collaboration., Context. While Euclid is an ESA mission specifically designed to investigate the nature of dark energy and dark matter, the planned unprecedented combination of survey area (∼15 000 deg2), spatial resolution, low sky-background, and depth also make Euclid an excellent space observatory for the study of the low surface brightness Universe. Scientific exploitation of the extended low surface brightness structures requires dedicated calibration procedures that are yet to be tested. Aims. We investigate the capabilities of Euclid to detect extended low surface brightness structure by identifying and quantifying sky-background sources and stray-light contamination. We test the feasibility of generating sky flat-fields to reduce large-scale residual gradients in order to reveal the extended emission of galaxies observed in the Euclid survey. Methods. We simulated a realistic set of Euclid/VIS observations, taking into account both instrumental and astronomical sources of contamination, including cosmic rays, stray-light, zodiacal light, interstellar medium, and the cosmic infrared background, while simulating the effects of background sources in the field of view. Results. We demonstrate that a combination of calibration lamps, sky flats, and self-calibration would enable recovery of emission at a limiting surface brightness magnitude of μlim = 29.5−0.27+0.08 mag arcsec−2 (3σ, 10 × 10 arcsec2) in the Wide Survey, and it would reach regions deeper by 2 mag in the Deep Surveys. Conclusions.Euclid/VIS has the potential to be an excellent low surface brightness observatory. Covering the gap between pixel-to-pixel calibration lamp flats and self-calibration observations for large scales, the application of sky flat-fielding will enhance the sensitivity of the VIS detector at scales larger than 1″, up to the size of the field of view, enabling Euclid to detect extended surface brightness structures below μlim = 31 mag arcsec−2 and beyond. © ESO 2022., A. B. was supported by an appointment to the NASA Postdoctoral Program at the NASA Ames Research Center, administered by Universities Space Research Association under contract with NASA, and the European Space Agency (ESA), through the European Space Astronomy Center Faculty. We acknowledge a number of agencies and institutes that have supported the development of Euclid, in particular the Academy of Finland, the Agenzia Spaziale Italiana, the Belgian Science Policy, the Canadian Euclid Consortium, the Centre National d’Etudes Spatiales, the Deutsches Zentrum für Luft- und Raumfahrt, the Danish Space Research Institute, the Fundação para a Ciência e a Tecnologia, the Ministerio de Economia y Competitividad, the National Aeronautics and Space Administration, the National Astronomical Observatory of Japan, the Netherlandse Onderzoekschool Voor Astronomie, the Norwegian Space Agency, the Romanian Space Agency, the State Secretariat for Education, Research and Innovation (SERI) at the Swiss Space Office (SSO), and the United Kingdom Space Agency. A complete and detailed list is available on the Euclid website (http://www.euclid-ec.org). This work has made use of data from the ESA mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This research made use of NumPy (Van Der Walt et al. 2011), Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration 2013). All of the figures on this publication were generated using Matplotlib (Hunter 2007). This work was partly done using GNU Astronomy Utilities (Gnuastro, ascl.net/1801.009) version 0.11.22-dc86., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

Explaining the existence of super massive black holes (SMBHs) with MBH ≳ 108 M⊙ at z ≳ 6 is a persistent challenge to modern astrophysics. Multiwavelength observations of z ≳ 6 quasi-stellar objects (QSOs) reveal that, on average, their accretion physics is similar to that of their counterparts at lower redshift. However, QSOs showing properties that deviate from the general behavior can provide useful insights into the physical processes responsible for the rapid growth of SMBHs in the early universe. We present X-ray (XMM-Newton, 100 ks) follow-up observations of a z ≈ 6 QSO, J1641+3755, which was found to be remarkably X-ray bright in a 2018 Chandra dataset. J1641+3755 is not detected in the 2021 XMM-Newton observation, implying that its X-ray flux decreased by a factor ≳7 on a notably short timescale (i.e., ≈115 rest-frame days), making it the z > 4 QSO with the largest variability amplitude. We also obtained rest-frame ultraviolet (UV) spectroscopic and photometric data with the Large Binocular Telescope (LBT). Surprisingly, comparing our LBT photometry with archival data, we found that J1641+3755 became consistently brighter in the rest-frame UV band from 2003 to 2016, while no strong variation occurred from 2016 to 2021. Its rest-frame UV spectrum is consistent with the average spectrum of high-redshift QSOs. Multiple narrow absorption features are present, and several of them can be associated with an intervening system at z = 5.67. Several physical causes can explain the variability properties of J1641+3755, including intrinsic variations of the accretion rate, a small-scale obscuration event, gravitational lensing due to an intervening object, and an unrelated X-ray transient in a foreground galaxy in 2018. Accounting for all of the z > 6 QSOs with multiple X-ray observations separated by more that ten rest-frame days, we found an enhancement of strongly (i.e., by a factor > 3) X-ray variable objects compared to QSOs at later cosmic times. This finding may be related to the physics of fast accretion in high-redshift QSOs.

M.Ferrais et al., [Context] Asteroid (22) Kalliope is the second largest M-type asteroid in the main belt and is orbited by a satellite, Linus. Whereas the mass of Kalliope is already well constrained thanks to the presence of a moon, its volume is still poorly known, leading to uncertainties on its bulk density and internal structure., [Aims] We aim to refine the shape of (22) Kalliope and thus its diameter and bulk density, as well as the orbit of its moon to better constrain its mass, hence density and internal structure., [Methods] We acquired disk-resolved observations of (22) Kalliope using the VLT/SPHERE/ZIMPOL instrument to reconstruct its three-dimensional (3D) shape using three different modeling techniques. These images were also used together with new speckle observations at the C2PU/PISCO instrument as well as archival images from other large ground-based telescopes to refine the orbit of Linus., [Results] The volume of (22) Kalliope given by the shape models, corresponding to D = 150 ± 5 km, and the mass constrained by its satellite’s orbit yield a density of ρ = 4.40 ± 0.46 g cm−3. This high density potentially makes (22) Kalliope the densest known small body in the Solar System. A macroporosity in the 10–25% range (as expected for this mass and size), implies a grain density in the 4.8–5.9 g cm−3 range. Kalliope’s high bulk density, along with its silicate-rich surface implied by its low radar albedo, implies a differentiated interior with metal contributing to most of the mass of the body., [Conclusions] Kalliope’s high metal content (40–60%) along with its metal-poor mantle makes it the smallest known Mercury-like body. A large impact at the origin of the formation of the moon Linus is likely the cause of its high metal content and density., Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 199.C-0074 (PI: P. Vernazza). P. V., A. D., M. F. and B. C. were supported by CNRS/INSU/PNP. The research of J.H. has been supported by the Czech Science Foundation through grant 20-08218S and by Charles University Research program no. UNCE/SCI/023. M.B. was supported by the Czech Science Foundation, grant 21-11058S. F.M. is supported by the National Science Foundation under grant no. 1743015. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant PDR T.0120.21. TRAPPIST-North is a project funded by the University of Liège, in collaboration with the Cadi Ayyad University of Marrakech (Morocco). E.J. is F.R.S.-FNRS Senior Research Associate. The work of T.S.R. was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE).

Recent studies based on photometry from the Transiting Exoplanet Survey Satellite (TESS) have suggested that the dayside of KELT-1b, a strongly irradiated brown dwarf, is significantly brighter in visible light than what would be expected based on Spitzer observations in the infrared. We observed eight eclipses of KELT-1b with CHaracterising ExOPlanet Satellite (CHEOPS) to measure its dayside brightness temperature in the bluest passband observed so far, and we jointly modelled the CHEOPS photometry with the existing optical and near-infrared photometry from TESS, LBT, CFHT, and Spitzer. Our modelling has led to a self-consistent dayside spectrum for KELT-1b covering the CHEOPS, TESS, H, Ks, and Spitzer IRAC 3.6 and 4.5 μm bands, where our TESS, H, Ks, and Spitzer band estimates largely agree with the previous studies. However, we discovered a strong discrepancy between the CHEOPS and TESS bands. The CHEOPS observations yield a higher photometric precision than the TESS observations, but they do not show a significant eclipse signal, while a deep eclipse is detected in the TESS band. The derived TESS geometric albedo of 0.36-0.13+0.12 is difficult to reconcile with a CHEOPS geometric albedo that is consistent with zero because the two passbands have considerable overlap. Variability in cloud cover caused by the transport of transient nightside clouds to the dayside could provide an explanation for reconciling the TESS and CHEOPS geometric albedos, but this hypothesis needs to be tested by future observations., Astronomy & Astrophysics, 668, ISSN:0004-6361, ISSN:1432-0746

Full list of authors: Kahil, F.; Hirzberger, J.; Solanki, S. K.; Chitta, L. P.; Peter, H.; Auchère, F.; Sinjan, J.; Orozco Suárez, D.; Albert, K.; Albelo Jorge, N.; Appourchaux, T.; Alvarez-Herrero, A.; Blanco Rodríguez, J.; Gandorfer, A.; Germerott, D.; Guerrero, L.; Gutiérrez Márquez, P.; Kolleck, M.; del Toro Iniesta, J. C.; Volkmer, R. ; Woch, J.; Fiethe, B.; Gómez Cama, J. M.; Pérez-Grande, I.; Sanchis Kilders, E.; Balaguer Jiménez, M.; Bellot Rubio, L. R.; Calchetti, D.; Carmona, M.; Deutsch, W.; Fernández-Rico, G.; Fernández-Medina, A.; García Parejo, P.; Gasent-Blesa, J. L.; Gizon, L.; Grauf, B.; Heerlein, K.; Lagg, A.; Lange, T.; López Jiménez, A.; Maue, T.; Meller, R.; Michalik, H.; Moreno Vacas, A.; Müller, R.; Nakai, E.; Schmidt, W.; Schou, J.; Schühle, U.; Staub, J.; Strecker, H.; Torralbo, I.; Valori, G.; Aznar Cuadrado, R.; Teriaca, L.; Berghmans, D.; Verbeeck, C.; Kraaikamp, E.; Gissot, S.-- This is an Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., Context. The Extreme Ultraviolet Imager (EUI) on board the Solar Orbiter (SO) spacecraft observed small extreme ultraviolet (EUV) bursts, termed campfires, that have been proposed to be brightenings near the apexes of low-lying loops in the quiet-Sun atmosphere. The underlying magnetic processes driving these campfires are not understood. Aims. During the cruise phase of SO and at a distance of 0.523 AU from the Sun, the Polarimetric and Helioseismic Imager on Solar Orbiter (SO/PHI) observed a quiet-Sun region jointly with SO/EUI, offering the possibility to investigate the surface magnetic field dynamics underlying campfires at a spatial resolution of about 380 km. Methods. We used co-spatial and co-temporal data of the quiet-Sun network at disc centre acquired with the High Resolution Imager of SO/EUI at 17.4 nm (HRIEUV, cadence 2 s) and the High Resolution Telescope of SO/PHI at 617.3 nm (HRT, cadence 2.5 min). Campfires that are within the SO/PHI−SO/EUI common field of view were isolated and categorised according to the underlying magnetic activity. Results. In 71% of the 38 isolated events, campfires are confined between bipolar magnetic features, which seem to exhibit signatures of magnetic flux cancellation. The flux cancellation occurs either between the two main footpoints, or between one of the footpoints of the loop housing the campfire and a nearby opposite polarity patch. In one particularly clear-cut case, we detected the emergence of a small-scale magnetic loop in the internetwork followed soon afterwards by a campfire brightening adjacent to the location of the linear polarisation signal in the photosphere, that is to say near where the apex of the emerging loop lays. The rest of the events were observed over small scattered magnetic features, which could not be identified as magnetic footpoints of the campfire hosting loops. Conclusions. The majority of campfires could be driven by magnetic reconnection triggered at the footpoints, similar to the physical processes occurring in the burst-like EUV events discussed in the literature. About a quarter of all analysed campfires, however, are not associated to such magnetic activity in the photosphere, which implies that other heating mechanisms are energising these small-scale EUV brightenings. © F. Kahil et al. 2022., Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA. We are grateful to the ESA SOC and MOC teams for their support. The German contribution to SO/PHI is funded by the BMWi through DLR and by MPG central funds. The Spanish contribution is funded by FEDER/AEI/MCIU (RTI2018-096886-C5), a “Center of Excellence Severo Ochoa” award to IAA-CSIC (SEV-2017-0709), and a Ramón y Cajal fellowship awarded to DOS. The French contribution is funded by CNES. The EUI instrument was built by CSL, IAS, MPS, MSSL/UCL, PMOD/WRC, ROB, LCF/IO with funding from the Belgian Federal Science Policy Office (BELSPO/PRODEX PEA 4000112292); the Centre National d’Etudes Spatiales (CNES); the UK Space Agency (UKSA); the Bundesministerium für Wirtschaft und Energie (BMWi) through the Deutsches Zentrum für Luft- und Raumfahrt (DLR); and the Swiss Space Office (SSO).

Context. Our knowledge of populations and occurrence of planets orbiting evolved intermediate-mass stars is still incomplete. In 2010 we started a planet-search program among 95 giant stars observed by the Kepler mission to increase the sample of giant stars with planets and with reliable estimates of stellar masses and radii. Aims. We present the two systems KIC 3526061 and HD 187878 from our planet-search program for which we could characterise their companions. Methods. We used precise stellar radial velocity measurements taken with four different echelle spectrographs to derive an orbital solution. We used Gaia astrometric measurements to obtain the inclination of the HD 187878 system and Kepler photometric observations to estimate the stellar mass and radius. Results. We report the discovery of a sub-stellar and a stellar companion around two intermediate-mass red giant branch stars. KIC 3526061 b is most likely a brown dwarf with a minimum mass of 18.15 Jupiter masses in a long-period eccentric orbit, with the orbital period 3552 d and orbital eccentricity 0.85. It is the most evolved system found having a sub-stellar companion with such a large eccentricity and wide separation. HD 187878 B has a minimum mass of 78.4 Jupiter masses. Combining the spectroscopic orbital parameters with the astrometric proper motion anomaly we derived an orbital inclination 9.8 deg, which corresponds to the companion's mass in the stellar regime of 0.51 Sun mass. Conclusions. A sub-stellar companion of KIC 3526061 extends the sample of known red giant branch stars with sub-stellar companions on very eccentric wide orbits and might provide a probe of the dynamical evolution of such systems over time., 14 pages, 11 figures. Accepted to A&A

We report our new spectropolarimetric observations for 67P dust over 4,000--9,000 Angstrom using the ESO/Very Large Telescope in January--March 2016 (phase angle ranging $\sim$26--5 deg) to constrain the properties of the dust particles of 67P and therefrom diagnose the dust environment of its coma and near-surface layer at around the end of the Southern summer of the comet. We examined the optical behaviours of the dust, which, together with Rosetta colour data, were used to search for dust evolution with cometocentric distance. Modelling was also conducted to identify the dust attributes compatible with the results. The spectral dependence of the polarisation degree of 67P dust is flatter than found in other dynamical groups of comets in similar observing geometry. The depth of its negative polarisation branch appears to be a bit shallower than in long-period comets and might be getting shallower as 67P repeats its apparitions. Its dust colour shows a change in slope around 5,500 Angstrom, (17.3 $\pm$ 1.4) and (10.9 $\pm$ 0.6) % (1,000 Angstrom)$^{\rm -1}$ for shortward and longward of the wavelength, respectively, which are slightly redder but broadly consistent with the average of Jupiter-Family comets. Observations of 67P dust in this study can be attributed to dust agglomerates of $\sim$100 $\mu$m in size detected by Rosetta in early 2016. A porosity of 60 % shows the best match with our polarimetric results, yielding a dust density of $\sim$770 kg m$^{\rm -3}$. Compilation of Rosetta and our data indicates the dust's reddening with increasing nucleus distance, which may be driven by water-ice sublimation as the dust moves out of the nucleus. We estimate the possible volume fraction of water ice in the initially ejected dust as $\sim$6 % (i.e. the refractory-to-ice volume ratio of $\sim$14)., Comment: Accepted for publication in Astronomy & Astrophysics

J.M.O. acknowledges financial support from the Portuguese Foundation for Science and Technology (FCT) and the European Social Fund (ESF) through the PhD grant SFRH/BD/131700/2017. The work leading to these results has received funding from the European Research Council under the European Community's H2020 2014-2021 ERC grant Agreement nffi 669416 "Lucky Star". We thank S. Para who supported some travels to observe the 5 October 2017 occultation. T.B. was supported for this research by an appointment to the National Aeronautics and Space Administration (NASA) Post-Doctoral Program at the Ames Research Center administered by Universities Space Research Association (USRA) through a contract with NASA. We acknowledge useful exchanges with Mark Gurwell on the ALMA CO observations. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. J.L.O., P.S.-S., N.M. and R.D. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709), they also acknowledge the financial support by the Spanish grant AYA-2017-84637-R and the Proyecto de Excelencia de la Junta de Andalucia J.A. 2012-FQM1776. The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement no. 687378, as part of the project "Small Bodies Near and Far" (SBNAF). P.S.-S. acknowledges financial support by the Spanish grant AYA-RTI2018-098657-J-I00 "LEO-SBNAF". The work was partially based on observations made at the Laboratorio Nacional de Astrofisica (LNA), Itajuba-MG, Brazil. The following authors acknowledge the respective CNPq grants: F.B.-R. 309578/2017-5; R.V.-M. 304544/2017-5, 401903/2016-8; J.I.B.C. 308150/2016-3 and 305917/2019-6; M.A. 427700/20183, 310683/2017-3, 473002/2013-2. This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior -Brasil (CAPES) -Finance Code 001 and the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo, CNPq grant 465376/2014-2). G.B.R. acknowledges CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016 and CAPES-PRINT/UNESP grant 88887.571156/2020-00, M.A. FAPERJ grant E26/111.488/2013 and A.R.G.Jr. FAPESP grant 2018/11239-8. B.E.M. thanks CNPq 150612/2020-6 and CAPES/Cofecub-394/2016-05 grants. Part of the photometric data used in this study were collected in the frame of the photometric observations with the robotic and remotely controlled telescope at the University of Athens Observatory (UOAO; Gazeas 2016). The 2.3 m Aristarchos telescope is operated on Helmos Observatory by the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens. Observations with the 2.3 m Aristarchos telescope were carried out under OPTICON programme. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730890. This material reflects only the authors views and the Commission is not liable for any use that may be made of the information contained therein. The 1. 2m Kryoneri telescope is operated by the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens. The Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVdA) is managed by the Fondazione Clement Fillietroz-ONLUS, which is supported by the Regional Government of the Aosta Valley, the Town Municipality of Nus and the "Unite des Communes valdotaines Mont-Emilius". The 0.81 m Main Telescope at the OAVdA was upgraded thanks to a Shoemaker NEO Grant 2013 from The Planetary Society. D.C. and J.M.C. acknowledge funds from a 2017 'Research and Education' grant from Fondazione CRT-Cassa di Risparmio di Torino. P.M. acknowledges support from the Portuguese Fundacao para a Ciencia e a Tecnologia ref. PTDC/FISAST/29942/2017 through national funds and by FEDER through COMPETE 2020 (ref. POCI010145 FEDER007672). F.J. acknowledges Jean Luc Plouvier for his help. S.J.F. and C.A. would like to thank the UCL student support observers: Helen Dai, Elise Darragh-Ford, Ross Dobson, Max Hipperson, Edward Kerr-Dineen, Isaac Langley, Emese Meder, Roman Gerasimov, Javier Sanjuan, and Manasvee Saraf. We are grateful to the CAHA, OSN and La Hita Observatory staffs. This research is partially based on observations collected at Centro Astronomico HispanoAleman (CAHA) at Calar Alto, operated jointly by Junta de Andalucia and Consejo Superior de Investigaciones Cientificas (IAA-CSIC). This research was also partially based on observation carried out at the Observatorio de Sierra Nevada (OSN) operated by Instituto de Astrofisica de Andalucia (CSIC). This article is also based on observations made with the Liverpool Telescope operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. Partially based on observations made with the Tx40 and Excalibur telescopes at the Observatorio Astrofisico de Javalambre in Teruel, a Spanish Infraestructura Cientifico-Tecnica Singular (ICTS) owned, managed and operated by the Centro de Estudios de Fisica del Cosmos de Aragon (CEFCA). Tx40 and Excalibur are funded with the Fondos de Inversiones de Teruel (FITE). A.R.R. would like to thank Gustavo Roman for the mechanical adaptation of the camera to the telescope to allow for the observation to be recorded. R.H., J.F.R., S.P.H. and A.S.L. have been supported by the Spanish projects AYA2015-65041P and PID2019-109467GB-100 (MINECO/FEDER, UE) and Grupos Gobierno Vasco IT1366-19. Our great thanks to Omar Hila and their collaborators in Atlas Golf Marrakech Observatory for providing access to the T60cm telescope. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant PDR T.0120.21. TRAPPIST-North is a project funded by the University of Liege, and performed in collaboration with Cadi Ayyad University of Marrakesh. E.J. is a FNRS Senior Research Associate., Context. A stellar occultation by Neptune's main satellite, Triton, was observed on 5 October 2017 from Europe, North Africa, and the USA. We derived 90 light curves from this event, 42 of which yielded a central flash detection. Aims. We aimed at constraining Triton's atmospheric structure and the seasonal variations of its atmospheric pressure since the Voyager 2 epoch (1989). We also derived the shape of the lower atmosphere from central flash analysis. Methods. We used Abel inversions and direct ray-tracing code to provide the density, pressure, and temperature profiles in the altitude range similar to 8 km to similar to 190 km, corresponding to pressure levels from 9 mu bar down to a few nanobars. Results. (i) A pressure of 1.18 +/- 0.03 mu bar is found at a reference radius of 1400 km (47 km altitude). (ii) A new analysis of the Voyager 2 radio science occultation shows that this is consistent with an extrapolation of pressure down to the surface pressure obtained in 1989. (iii) A survey of occultations obtained between 1989 and 2017 suggests that an enhancement in surface pressure as reported during the 1990s might be real, but debatable, due to very few high S/N light curves and data accessible for reanalysis. The volatile transport model analysed supports a moderate increase in surface pressure, with a maximum value around 2005-2015 no higher than 23 mu bar. The pressures observed in 1995-1997 and 2017 appear mutually inconsistent with the volatile transport model presented here. (iv) The central flash structure does not show evidence of an atmospheric distortion. We find an upper limit of 0.0011 for the apparent oblateness of the atmosphere near the 8 km altitude., Portuguese Foundation for Science and Technology SFRH/BD/131700/2017, European Social Fund (ESF) SFRH/BD/131700/2017, European Research Council under the European Community's H2020 2014-2021 ERC grant 669416, Spanish Government SEV-2017-0709 AYA-2017-84637-R AYA-RTI2018-098657-J-I00, Junta de Andalucia 2012-FQM1776, European Union's Horizon 2020 Research and Innovation Programme, as part of the project "Small Bodies Near and Far" (SBNAF) 687378, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ), Fundacao de Apoio a Pesquisa do Distrito Federal (FAPDF) 309578/2017-5 304544/2017-5 401903/2016-8 308150/2016-3 305917/2019-6 427700/2018-3 310683/2017-3 473002/2013-2, Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) 001, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) 465376/2014-2 CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016 CAPES-PRINT/UNESP grant 88887.571156/2020-00, Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio De Janeiro (FAPERJ) E26/111.488/2013, Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) 2018/11239-8, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) 150612/2020-6, European Union's Horizon 2020 research and innovation programme 730890, Regional Government of the Aosta Valley, Town Municipality of Nus, Unite des Communes valdotaines Mont-Emilius, Planetary Society, Fondazione CRT-Cassa di Risparmio di Torino, Portuguese Foundation for Science and Technology PTDC/FISAST/29942/2017, FEDER through COMPETE 2020 POCI010145 FEDER007672, UK Research & Innovation (UKRI), Science & Technology Facilities Council (STFC), Fondos de Inversiones de Teruel (FITE), Spanish Government AYA2015-65041P PID2019-109467GB-100, Grupos Gobierno Vasco IT1366-19, Fonds de la Recherche Scientifique - FNRS PDR T.0120.21, University of Liege, CAPES/Cofecub-394/2016-05

This is an Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., Context. Cybele asteroids constitute an appealing reservoir of primitive material genetically linked to the outer Solar System, and the physical properties (size and shape) of the largest members can be readily accessed by large (8m class) telescopes. Aims. We took advantage of the bright apparition of the most iconic member of the Cybele population, (65) Cybele, in July and August 2021 to acquire high-angular-resolution images and optical light curves of the asteroid with which we aim to analyse its shape and bulk properties. Methods. Eight series of images were acquired with VLT/SPHERE+ZIMPOL, seven of which were combined with optical light curves to reconstruct the shape of the asteroid using the ADAM, MPCD, and SAGE algorithms. The origin of the shape was investigated by means of N-body simulations. Results. Cybele has a volume-equivalent diameter of 263±3 km and a bulk density of 1.55 ± 0.19 g cm−3. Notably, its shape and rotation state are closely compatible with those of a Maclaurin equilibrium figure. The lack of a collisional family associated with Cybele and the higher bulk density of that body with respect to other large P-type asteroids suggest that it never experienced any large disruptive impact followed by rapid re-accumulation. This would imply that its present-day shape represents the original one. However, numerical integration of the long-term dynamical evolution of a hypothetical family of Cybele shows that it is dispersed by gravitational perturbations and chaotic diffusion over gigayears of evolution. Conclusions. The very close match between Cybele and an equilibrium figure opens up the possibility that D ≥ 260 km (M ≥ 1.5 × 1019 kg) small bodies from the outer Solar System all formed at equilibrium. However, we cannot currently rule out an old impact as the origin of the equilibrium shape of Cybele. Cybele itself is found to be dynamically unstable, implying that it was ‘recently’ (, Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO program 107.22QN.001 (PI: Marsset). This research has made use of IMCCE’s SsOD-Net VO tool (https://ssp.imcce.fr/webservices/ssodnet/). This work has been supported by the Czech Science Foundation through grants 20-08218S (J. Hanuš) and 21-11058S (M. Brož), as well as by the National Science Foundation under Grant No. 1743015 (F. Marchis). T. Santana-Ros acknowledges funding from the NEO-MAPP project (H2020-EU-2-1-6/870377). In addition, this work was partially funded by the Spanish MICIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” by the “European Union” through grant RTI2018-095076-B-C21, and the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia ‘María de Maeztu’) through grant CEX2019-000918-M. This research has made use of the Asteroid Families Portal maintained at the Department of Astronomy, University of Belgrade. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant PDR T.0120.21. TRAPPIST-North is a project funded by the University of Liège, in collaboration with the Cadi Ayyad University of Marrakech (Morocco). E. Jehin is F.R.S.-FNRS Senior Research Associate., With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001131-S).

Past occultation and phase-curve observations of the ultra-short period super-Earth 55 Cnc e obtained at visible and infrared wavelengths have been challenging to reconcile with a planetary reflection and emission model. In this study, we analyse a set of 41 occultations obtained over a two-year timespan with the CHEOPS satellite. We report the detection of 55 Cnc e's occultation with an average depth of 12 ± 3 ppm. We derive a corresponding 2Ïà  upper limit on the geometric albedo of Ag < 0.55 once decontaminated from the thermal emission measured by Spitzer at 4.5 μm. CHEOPSâà €à ™ s photometric performance enables, for the first time, the detection of individual occultations of this super-Earth in the visible and identifies short-timescale photometric corrugations likely induced by stellar granulation. We also find a clear 47.3-day sinusoidal pattern in the time-dependent occultation depths that we are unable to relate to stellar noise, nor instrumental systematics, but whose planetary origin could be tested with upcoming JWST occultation observations of this iconic super-Earth., Astronomy & Astrophysics, 669, ISSN:0004-6361, ISSN:1432-0746

Upcoming cosmological intensity mapping surveys will open new windows on the Universe, but they must first overcome a number of significant systematic effects, including polarization leakage. We present a formalism that uses scan strategy information to model the effect of different instrumental systematics on the recovered cosmological intensity signal for `single-dish' (autocorrelation) surveys. This modelling classifies different systematics according to their spin symmetry, making it particularly relevant for dealing with polarization leakage. We show how to use this formalism to calculate the expected contamination from different systematics as a function of the scanning strategy. Most importantly, we show how systematics can be disentangled from the intensity signal based on their spin properties via map-making. We illustrate this, using a set of toy models, for some simple instrumental systematics, demonstrating the ability to significantly reduce the contamination to the observed intensity signal. Crucially, unlike existing foreground removal techniques, this approach works for signals that are non-smooth in frequency, e.g. polarized foregrounds. These map-making approaches are simple to apply and represent an orthogonal and complementary approach to existing techniques for removing systematics from upcoming 21cm intensity mapping surveys.

We present detailed investigation of a specific i-band light-curve feature in Type Ia supernovae (SNe Ia) using the rapid cadence and high signal-to-noise ratio light curves obtained by the Carnegie Supernova Project. The feature is present in most SNe Ia and emerges a few days after the i-band maximum. It is an abrupt change in curvature in the light curve over a few days and appears as a flattening in mild cases and a strong downward concave shape, or a ‘kink’, in the most extreme cases. We computed the second derivatives of Gaussian Process interpolations to study 54 rapid-cadence light curves. From the second derivatives we measure: (1) the timing of the feature in days relative to i-band maximum; tdm2(i) and (2) the strength and direction of the concavity in mag d−2; dm2(i). 76 per cent of the SNe Ia show a negative dm2(i), representing a downward concavity – either a mild flattening or a strong ‘kink’. The tdm2(i) parameter is shown to correlate with the colour-stretch parameter sBV, a SN Ia primary parameter. The dm2(i) parameter shows no correlation with sBV and therefore provides independent information. It is also largely independent of the spectroscopic and environmental properties. Dividing the sample based on the strength of the light-curve feature as measured by dm2(i), SNe Ia with strong features have a Hubble diagram dispersion of 0.107 mag, 0.075 mag smaller than the group with weak features. Although larger samples should be obtained to test this result, it potentially offers a new method for improving SN Ia distance determinations without shifting to more costly near-infrared or spectroscopic observations., The work of the CSP has been supported by the National Science Foundation under grants AST0306969, AST0607438, AST1008343, AST1613426, AST1613455, and AST1613472. PJP thanks the kindness and support of the FSU SN team. LG acknowledges financial support from the Spanish Ministry of Science and Innovation (MCIN) under the 2019 Ramón y Cajal program RYC2019-027683 and from the Spanish MCIN project HOSTFLOWS PID2020-115253GA-I00. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

We study the most precise light curves of the planet-host HAT-P-36 that we obtained from the ground primarily with a brand-new 80 cm telescope very recently installed at Ankara University Kreiken Observatory of Turkey and also from the space with Transiting Exoplanet Survey Satellite. The main objective of the study is to analyze the Transit Timing Variations (TTV) observed in the hot-Jupiter type planet HAT-P-36 b, a strong candidate for orbital decay, based on our own observations as well as that have been acquired by professional and amateur observers since its discovery. HAT-P-36 displays out-of-transit variability as well as light curve anomalies during the transits of its planet due to stellar spots. We collected and detrended all the complete transit light curves we had access to from these anomalies, which we modeled with EXOFAST and measured the mid-transit times forming a homogeneous data set for a TTV analysis. We found an increase in the orbital period of HAT-P-36 b at a rate of 0.014 s per year from the best fitting quadratic function, which is only found in the TTV constructed by making use of the mid-transit times measured from detrended light curves, against an expectation of an orbital decay based on its parameters. We refined the values of these system parameters by modeling the Spectral Energy Distribution of the host star, its archival radial velocity observations from multiple instruments, and most precise transit light curves from the space and the ground covering a wide range of wavelengths with EXOFASTV2. We also analyzed the out-of-transit variability from TESS observations to search for potential rotational modulations through a frequency analysis. We report a statistically significant periodicity in the TESS light curve at 4.22 +/- 0.02 d, which might have been caused by instrumental systematics but should be tracked in the future observations of the target.

Context: Gas accretion flows transport material from the cloud core onto the protostar. In multiple protostellar systems, it is not clear if the delivery mechanism is preferential or evenly distributed among the components. Aims: Gas accretion flows within IRAS16293 is explored out to 6000 AU. Methods: ALMA Band 3 observations of low-$J$ transitions of HNC, cyanopolyynes (HC$_3$N, HC$_5$N), and N$_2$H$^+$ are used to probe the cloud core structure at ~100 AU resolution. Additional Band 3 archival data provide low-$J$ HCN and SiO lines. These data are compared with the corresponding higher-$J$ lines from the PILS Band 7 data for excitation analysis. The HNC/HCN ratio is used as a temperature tracer. Results: The low-$J$ transitions of HC$_3$N, HC$_5$N, HNC and N$_2$H$^+$ trace extended and elongated structures from 6000 AU down to ~100 AU, without accompanying dust continuum emission. Two structures are identified: one traces a flow that is likely accreting toward the most luminous component of the system IRAS16293 A. Temperatures inferred from the HCN/HNC ratio suggest that the gas in this flow is cold, between 10 and 30 K. The other structure is part of an UV-irradiated cavity wall entrained by one of the outflows. The two outflows driven by IRAS16293 A present different molecular gas distributions. Conclusions: Accretion of cold gas is seen from 6000 AU scales onto IRAS16293 A, but not onto source B, indicates that cloud core material accretion is competitive due to feedback onto a dominant component in an embedded multiple protostellar system. The preferential delivery of material could explain the higher luminosity and multiplicity of source A compared to source B. The results of this work demonstrate that several different molecular species, and multiple transitions of each species, are needed to confirm and characterize accretion flows in protostellar cloud cores., 17 pages, 10 figures, accepted for publication in A&A

Vernazza, P., et al., Until recently, the 3D shape, and therefore density (when combining the volume estimate with available mass estimates), and surface topography of the vast majority of the largest (D ≥ 100 km) main-belt asteroids have remained poorly constrained. The improved capabilities of the SPHERE/ZIMPOL instrument have opened new doors into ground-based asteroid exploration. Aims. To constrain the formation and evolution of a representative sample of large asteroids, we conducted a high-angular-resolution imaging survey of 42 large main-belt asteroids with VLT/SPHERE/ZIMPOL. Our asteroid sample comprises 39 bodies with D ≥ 100 km and in particular most D ≥ 200 km main-belt asteroids (20/23). Furthermore, it nicely reflects the compositional diversity present in the main belt as the sampled bodies belong to the following taxonomic classes: A, B, C, Ch/Cgh, E/M/X, K, P/T, S, and V. Methods. The SPHERE/ZIMPOL images were first used to reconstruct the 3D shape of all targets with both the ADAM and MPCD reconstruction methods.We subsequently performed a detailed shape analysis and constrained the density of each target using available mass estimates including our own mass estimates in the case of multiple systems. Results. The analysis of the reconstructed shapes allowed us to identify two families of objects as a function of their diameters, namely spherical and elongated bodies. A difference in rotation period appears to be the main origin of this bimodality. In addition, all but one object (216 Kleopatra) are located along the Maclaurin sequence with large volatile-rich bodies being the closest to the latter. Our results further reveal that the primaries of most multiple systems possess a rotation period of shorter than 6 h and an elongated shape (c=a ≤ 0.65). Densities in our sample range from ∼1.3 g cm-3 (87 Sylvia) to ∼4.3 g cm-3 (22 Kalliope). Furthermore, the density distribution appears to be strongly bimodal with volatile-poor (P ≥ 2.7 g cm-3) and volatile-rich (P ≤ 2.2 g cm-3) bodies. Finally, our survey along with previous observations provides evidence in support of the possibility that some C-complex bodies could be intrinsically related to IDP-like P- and D-type asteroids, representing different layers of a same body (C: core; P/D: outer shell). We therefore propose that P/ D-types and some C-types may have the same origin in the primordial trans-Neptunian disk., We warmly thank the ESO staff at Paranal and in particular Henri Boffin for providing us precious support and advice throughout the entire observing programme. P.V., A.D., M.F., L.J. and B.C. were supported by CNRS/INSU/PNP. The work of T.S-R. was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). TRAPPIST project is funded by the Belgian Fund for Scientic Research (Fond National de la Recherche Scientique, FNRS) under the grant PDR T.0120.21. E.J. is a FNRS Senior Research Associate. F.M. is supported by the National Science Foundation under Grant No. 1743015.

On 4 March 2021 at 9 UTC a 30-m in diameter near-Earth asteroid 2021 DW1 passed the Earth at a distance of 570000 km, reaching the maximum brightness of V=14.6 mag. We observed it photometrically from 2 March, when it was visible at V=16.5 mag, until 7 March (V=18.2 mag). During that time 2021 DW1 swept a 170 degrees long arc in the northern sky, spanning solar phase angles in the range from 36 to 86 degrees. This made it an excellent target for physical characterisation, including spin axis and shape derivation. Convex inversion of the asteroid lightcurves gives a sidereal period of rotation P=0.013760 +/- 0.000001 h, and two solutions for the spin axis ecliptic coordinates: (A) lambda_1=57 +/- 10, beta_1=29 +/- 10, and (B) lambda_2=67 +/- 10, beta_2=-40 +/- 10. The magnitude-phase curve can be fitted with a standard H, G function with H=24.8 +/- 0.5 mag and an assumed G=0.24. The asteroid colour indices are g-i=0.79 +/- 0.01 mag, and i-z=0.01 +/- 0.02 mag which indicates an S taxonomic class, with an average geometric albedo p_V=0.23 +/- 0.02. The asteroid effective diameter, derived from H and p_V, is D=30 +/- 10 m. It was found that the inclination of the spin axis of 2021 DW1 is not perpendicular to the orbital plane (obliquity epsilon=54 +/- 10 or epsilon=123 +/- 10). More spin axes of VSAs should be determined to check, if 2021 DW1 is an exception or a typical case., 9 pages, 9 figures, submitted to A&A (version after revision)

24 pags., 32 figs., 3 tabs., Context. The [CII] 158 μm far-infrared fine-structure line is one of the dominant cooling lines of the star-forming interstellar medium. Hence [CII] emission originates in and thus can be used to trace a range of ISM processes. Velocity-resolved large-scale mapping of [CII] in star-forming regions provides a unique perspective of the kinematics of these regions and their interactions with the exciting source of radiation. Aims. We explore the scientific applications of large-scale mapping of velocity-resolved [CII] observations. With the [CII] observations, we investigate the effect of stellar feedback on the ISM. We present the details of observation, calibration, and data reduction using a heterodyne array receiver mounted on an airborne observatory. Methods. A 1.15 square degree velocity-resolved map of the Orion molecular cloud centred on the bar region was observed using the German REceiver for Astronomy at Terahertz Frequencies (upGREAT) heterodyne receiver flying on board the Stratospheric Observatory for Infrared Astronomy. The data were acquired using the 14 pixels of the German REceiver for Astronomy at Terahertz Frequencies that were observed in an on-the-fly mapping mode. 2.4 million spectra were taken in total. These spectra were gridded into a three-dimensional cube with a spatial resolution of 14.1 arcseconds and a spectral resolution of 0.3 km s-1. Results. A square-degree [CII] map with a spectral resolution of 0.3 km s-1 is presented. The scientific potential of this data is summarized with discussion of mechanical and radiative stellar feedback, filament tracing using [CII], [CII] opacity effects, [CII] and carbon recombination lines, and [CII] interaction with the large molecular cloud. The data quality and calibration is discussed in detail, and new techniques are presented to mitigate the effects of unavoidable instrument deficiencies (e.g. baseline stability) and thus to improve the data quality. A comparison with a smaller [CII] map taken with the Herschel/Heterodyne Instrument for the Far-Infrared spectrometer is presented. Conclusions. Large-scale [CII] mapping provides new insight into the kinematics of the ISM. The interaction between massive stars and the ISM is probed through [CII] observations. Spectrally resolving the [CII] emission is necessary to probe the microphysics induced by the feedback of massive stars. We show that certain heterodyne instrument data quality issues can be resolved using a spline-based technique, and better data correction routines allow for more efficient observing strategies., This work is based on observations made with the NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA). SOFIA is jointly operated by the Universities Space Research Association, Inc.(USRA), under NASA contract NAS2-97001, and the Deutsches SOFIA Institut (DSI) under DLR contract 50 OK 0901 to the University of Stuttgart. This work is carried out within the Collaborative Research Centre 956, subproject [A4], funded by the Deutsche Forschungsgemeinschaft (DFG) – project ID 184018867. We thank the Spanish MICIU for funding support under grant AYA2017-85111-P.

Red quasi-stellar objects (QSOs) are a subset of the quasar population with colours consistent with reddening due to intervening dust. Recent work has demonstrated that red QSOs show special radio properties that fundamentally distinguish them from normal blue QSOs, specifically a higher incidence of low-power radio emission (1.4 GHz luminosities L1.4 ≈ 1025–1027 W Hz−1) that is physically compact when imaged by arcsecond-resolution radio surveys such as FIRST. In this work, we present e-MERLIN imaging of a set of intermediate-redshift (1.0 < z < 1.55), luminous (bolometric luminosities Lbol ≈ 1046–1047 erg s−1) red and normal QSOs carefully selected to have radio properties that span the range over which red QSOs show the most divergence from the general population. With an angular resolution 25× better than FIRST, we resolve structures within the host galaxies of these QSOs (>2 kpc). We report a statistically significant difference in the incidence of extended kpc-scale emission in red QSOs. From an analysis of the radio size distributions of the sample, we find that the excess radio emission in red QSOs can be attributed to structures that are confined to galaxy scales (10 kpc). Our results indicate that the primary mechanism that generates the enhanced radio emission in red QSOs is not directly connected with the nuclear engine or accretion disc, but is likely to arise from extended components such as AGN-driven jets or winds. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society., DJR and DMA acknowledge support from the UK Science and Technology Facilities Council (STFC) through ST/T000244/1. JM acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science, Innovation and Universities (MCIU) through the ‘Center of Excellence Severo Ochoa’ award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709) and from the grant RTI2018-096228-B-C31 (MICIU/FEDER, EU). e-MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC, part of UK Research and Innovation. Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. This work has made use of data from the European Space Agency (ESA) mission Gaia processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.

We present the Global Rapid Advanced Network Devoted to the Multi-messenger Addicts (GRANDMA). The network consists of 21 telescopes with both photometric and spectroscopic facilities. They are connected together thanks to a dedicated infrastructure. The network aims at coordinating the observations of large sky position estimates of transient events to enhance their follow-up and reduce the delay between the initial detection and optical confirmation. The GRANDMA programme mainly focuses on follow-up of gravitational-wave alerts to find and characterize the electromagnetic counterpart during the third observational campaign of the Advanced LIGO and Advanced Virgo detectors. But it allows for follow-up of any transient alerts involving neutrinos or gamma-ray bursts, even those with poor spatial localization. We present the different facilities, tools, and methods we developed for this network and show its efficiency using observations of LIGO/Virgo S190425z, a binary neutron star merger candidate.We furthermore report on allGRANDMAfollow-up observations performed during the first six months of the LIGO-Virgo observational campaign, and we derive constraints on the kilonova properties assuming that the events' locations were imaged by our telescopes. © 2019 The Author(s)., Parts of this research were conducted by the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav), through project number CE170100004. EJH acknowledges support from a Australian Research Council DECRA Fellowship (DE170100891). AdUP and CCT acknowledge support from Ramon y Cajal fellowships RyC-2012-09975 and RyC-201209984 and the Spanish Ministry of Economy and Competitiveness through project AYA2017-89384-P. DAK acknowledges support from the Spanish research projectAYA2017-89384-P. MBacknowledges funding as `personal tecnico de apoyo' under fellowship number PTA2016-13192-I. MC is supported by the David and Ellen Lee Postdoctoral Fellowship at the California Institute of Technology. SA is supported by the CNES Postdoctoral Fellowship at Laboratoire AstroParticule et Cosmologie. SA, AC, CL, and RM acknowledge the financial support of the UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02). SA and NL acknowledge the financial support of the Programme National Hautes Energies (PNHE). DT acknowledges the financial support of the Chinese Academy of Sciences (CAS) PIFI post-doctoral fellowship program (program C). UBAI acknowledges support from the Ministry of Innovative Development through projects FA-Atech-2018-392 and VA-FAF-2-010. IRiS has been carried out thanks to the support of the OCEVU Labex (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02) funded by the 'Investissements d'Avenir' French government program. IRiS and T120 thank all the Observatoire de Haute-Provence staff for the permanent support. SB, NK, RN, and MV acknowledge the Shota Rustaveli National Science Foundation (SRNSF grant No 218070). TAROT has been built with the support of the Institut National des Sciences de l'Univers, CNRS,France. TAROT is funded by theCNESand thanks the help of the technical staff of the Observatoire de Haute Provence, OSU-Pytheas.

NS acknowledges the support of the National Priorities Research Program (NPRP) grant #X-019-1-006 from the Qatar National Research Fund (a member of Qatar Foundation). ACC acknowledges support from the Science & Technology Facilities Council (STFC) consolidated grant number ST/R000824/1. SuperWASP, the Northern hemisphere WASP observatory, has been observing the skies from La Palma since 2004. In that time, more than 50 planets have been discovered with data contributions from SuperWASP. In the process of validating planets, many false-positive candidates have also been identified. The TESS telescope is set to begin observations of the northern sky in 2019. Similar to the WASP survey, the TESS pixel size is relatively large (13arcsec for WASP and 21arcsec for TESS), making it susceptible to many blended signals and false detections caused principally by grazing and blended stellar eclipsing binary systems. In order to reduce duplication of effort on targets, we present a catalogue of 1041 Northern hemisphere SuperWASP targets that have been rejected as planetary transits through follow-up observation. Publisher PDF

Boyajian's star is an apparently normal main sequence F-type star with a very unusual light curve. The dipping activity of the star, discovered during the Kepler mission, presents deep, asymmetric, and aperiodic events. Here we present high resolution spectroscopic follow-up during some dimming events recorded post-Kepler observations, from ground-based telescopes. We analise data from the HERMES, HARPS-N and FIES spectrographs to characterise the stellar atmosphere and to put some constraints on the hypotheses that have appeared in the literature concerning the occulting elements. The star's magnetism, if existing, is not extreme. The spots on the surface, if present, would occupy 0.02% of the area, at most. The chromosphere, irrespective of the epoch of observation, is hotter than the values expected from radiative equilibrium, meaning that the star has some degree of activity. We find no clear evidence of the interstellar medium nor exocoments being responsible for the dimmings of the light curve. However, we detect at 1-2 sigma level, a decrease of the radial velocity of the star during the first dip recorded after the \emph{\emph{Kepler}} observations. We claim the presence of an optically thick object with likely inclined and high impact parameter orbits that produces the observed Rossiter-McLaughlin effect., Comment: submitted to MNRAS

We use photometric and kinematic data from Gaia DR2 to explore the structure of the star forming region associated with the molecular cloud of Perseus. Apart from the two well known clusters, IC 348 and NGC 1333, we present five new clustered groups of young stars, which contain between 30 and 300 members, named Autochthe, Alcaeus, Heleus, Electryon and Mestor. We demonstrate these are co-moving groups of young stars, based on how the candidate members are distributed in position, proper motion, parallax and colour-magnitude space. By comparing their colour-magnitude diagrams to isochrones we show that they have ages between 1 and 5 Myr. Using 2MASS and WISE colours we find that the fraction of stars with discs in each group ranges from 10 to 50 percent. The youngest of the new groups is also associated with a reservoir of cold dust, according to the Planck map at 353 GHz. We compare the ages and proper motions of the five new groups to those of IC 348 and NGC 1333. Autochthe is clearly linked with NGC 1333 and may have formed in the same star formation event. The seven groups separate roughly into two sets which share proper motion, parallax and age: Heleus, Electryon, Mestor as the older set, and NGC 1333, Autochthe as the younger set. Alcaeus is kinematically related to the younger set, but at a more advanced age, while the properties of IC 348 overlap with both sets. All older groups in this star forming region are located at higher galactic latitude., Comment: 27 pages, 12 figures; Note added in proof; Added references

We investigate the atmospheric composition of the long period ($P_{\rm orb}=$ 10 days), eccentric exo-Saturn WASP-117b. WASP-117b could be in atmospheric temperature and chemistry similar to WASP-107b. In mass and radius WASP-117b is similar to WASP-39b, which allows a comparative study of these planets. We analyze a near-infrared transmission spectrum of WASP-117b taken with Hubble Space Telescope/WFC3 G141, which was reduced with two independent pipelines. High resolution measurements were taken with VLT/ESPRESSO in the optical. We report the robust ($3\sigma$) detection of a water spectral feature. Using a 1D atmosphere model with isothermal temperature, uniform cloud deck and equilibrium chemistry, the Bayesian evidence of a retrieval analysis of the transmission spectrum indicates a preference for a high atmospheric metallicity ${\rm [Fe/H]}=2.58^{+0.26}_{-0.37}$ and clear skies. The data are also consistent with a lower-metallicity composition ${\rm [Fe/H]}, Comment: Accepted by A & A, 23 pages, 21 figures, + appendix (now transmission data appended)

There has been increasing progress toward detailed characterization of exoplanetary atmospheres, in both observations and theoretical methods. Improvements in observational facilities and data reduction and analysis techniques are enabling increasingly higher quality spectra, especially from ground-based facilities. The high data quality also necessitates concomitant improvements in models required to interpret such data. In particular, the detection of trace species such as metal oxides has been challenging. Extremely irradiated exoplanets (~3000 K) are expected to show oxides with strong absorption signals in the optical. However, there are only a few hot Jupiters where such signatures have been reported. Here we aim to characterize the atmosphere of the ultra-hot Jupiter WASP-33b using two primary transits taken 18 orbits apart. Our atmospheric retrieval, performed on the combined data sets, provides initial constraints on the atmospheric composition of WASP-33b. We report a possible indication of aluminum oxide (AlO) at 3.3-sigma significance. The data were obtained with the long slit OSIRIS spectrograph mounted at the 10-meter Gran Telescopio Canarias. We cleaned the brightness variations from the light curves produced by stellar pulsations, and we determined the wavelength-dependent variability of the planetary radius caused by the atmospheric absorption of stellar light. A simultaneous fit to the two transit light curves allowed us to refine the transit parameters, and the common wavelength coverage between the two transits served to contrast our results. Future observations with HST as well as other large ground-based facilities will be able to further constrain the atmospheric chemical composition of the planet., Comment: 15 pages, 11 figures

We observed two transits of the iconic gas giant HD 209458b between 380 and 780 nm, using the high-resolution ESPRESSO spectrograph. The derived planetary transmission spectrum exhibits features at all wavelengths where the parent star shows strong absorption lines, for example, NaI, MgI, FeI, FeII, CaI, VI, H$\alpha$, and KI. We interpreted these features as the signature of the deformation of the stellar line profiles due to the Rossiter-McLaughlin effect, combined with the centre-to-limb effects on the stellar surface, which is in agreement with similar reports recently presented in the literature. We also searched for species that might be present in the planetary atmosphere but not in the stellar spectra, such as TiO and VO, and obtained a negative result. Thus, we find no evidence of any planetary absorption, including previously reported NaI, in the atmosphere of HD 209458b. The high signal-to-noise ratio in the transmission spectrum allows us to compare the modelled deformation of the stellar lines in assuming different one-dimensional stellar atmospheric models. We conclude that the differences among various models and observations remain within the precision limits of the data. However, the transmission light curves are better explained when the centre-to-limb variation is not included in the computation and only the Rossiter-McLaughlin deformation is considered. This demonstrates that ESPRESSO is currently the best facility for spatially resolving the stellar surface spectrum in the optical range using transit observations and carrying out empirical validations of stellar models., Comment: 21 pages, 19 figures. Accepted

Measurements of exoplanetary orbital obliquity angles for different classes of planets are an essential tool in testing various planet formation theories. Measurements for those transiting planets on relatively large orbital periods (P > 10 d) present a rather difficult observational challenge. Here we present the obliquity measurement for the warm sub-Saturn planet HD 332231 b, which was discovered through Transiting Exoplanet Survey Satellite photometry of sectors 14 and 15, on a relatively large orbital period (18.7 d). Through a joint analysis of previously obtained spectroscopic data and our newly obtained CARMENES transit observations, we estimated the spin-orbit misalignment angle, λ, to be −42.0−10.6+11.3 deg, which challenges Laplacian ideals of planet formation. Through the addition of these new radial velocity data points obtained with CARMENES, we also derived marginal improvements on other orbital and bulk parameters for the planet, as compared to previously published values. We showed the robustness of the obliquity measurement through model comparison with an aligned orbit. Finally, we demonstrated the inability of the obtained data to probe any possible extended atmosphere of the planet, due to a lack of precision, and place the atmosphere in the context of a parameter detection space. © ESO 2022., CARMENES is an instrument at the Centro Astronómico Hispano-Alemán (CAHA) at Calar Alto (Almería, Spain), operated jointly by the Junta de Andalucía and the Instituto de Astrofísica de Andalucía (CSIC). The authors wish to express their sincere thanks to all members of the Calar Alto staff for their expert support of the instrument and telescope operation. We acknowledge financial support from the Agencia Estatal de Investigación of the Ministerio de Ciencia, Innovación y Universidades through projects Ref. PID2019-110689RB-I00/AEI/10.13039/501100011033 and the Centre of Excellence “Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). We also acknowledge the use of the ExoAtmospheres database during the preparation of this work and thank the team at the IAC for their excellent work preparing such a useful database. E.S. acknowledges support from ANID - Millennium Science Initiative - ICN12_009. K.M. acknowledges support from the Excellence Cluster ORIGINS, which is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy - EXC-2094 - 390783311. A.S.L. acknowledges funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program under grant agreement No 694513. Beside those explicitly mentioned in the manuscript, throughout this work the following python packages have been used: astropy (Astropy Collaboration 2018), corner (Foreman-Mackey 2016), matplotlib (Hunter 2007), NumPy (Harris et al. 2020), pandas (Pandas development team 2020), PyMC (Salvatier et al. 2016) and SciPy (Virtanen et al. 2020).

Full list of authors: Morgado, B. E.; Sicardy, B.; Braga-Ribas, F.; Desmars, J.; Gomes-Júnior, A. R.; Bérard, D.; Leiva, R.; Ortiz, J. L.; Vieira-Martins, R.; Benedetti-Rossi, G.; Santos-Sanz, P.; Camargo, J. I. B.; Duffard, R.; Rommel, F. L.; Assafin, M.; Boufleur, R. C.; Colas, F.; Kretlow, M.; Beisker, W.; Sfair, R.; Snodgrass, C.; Morales, N.; Fernández-Valenzuela, E.; Amaral, L. S.; Amarante, A.; Artola, R. A.; Backes, M.; Bath, K. -L.; Bouley, S.; Buie, M. W.; Cacella, P.; Colazo, C. A.; Colque, J. P.; Dauvergne, J. -L.; Dominik, M.; Emilio, M.; Erickson, C.; Evans, R.; Fabrega-Polleri, J.; Garcia-Lambas, D.; Giacchini, B. L.; Hanna, W.; Herald, D.; Hesler, G.; Hinse, T. C.; Jacques, C.; Jehin, E.; Jørgensen, U. G.; Kerr, S.; Kouprianov, V.; Levine, S. E.; Linder, T.; Maley, P. D.; Machado, D. I.; Maquet, L.; Maury, A.; Melia, R.; Meza, E.; Mondon, B.; Moura, T.; Newman, J.; Payet, T.; Pereira, C. L.; Pollock, J.; Poltronieri, R. C.; Quispe-Huaynasi, F.; Reichart, D.; de Santana, T.; Schneiter, E. M.; Sieyra, M. V.; Skottfelt, J.; Soulier, J. F.; Starck, M.; Thierry, P.; Torres, P. J.; Trabuco, L. L.; Unda-Sanzana, E.; Yamashita, T. A. R.; Winter, O. C.; Zapata, A.; Zuluaga, C. A.--This is an Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., Context. The Centaur (10199) Chariklo has the first ring system discovered around a small object. It was first observed using stellar occultation in 2013. Stellar occultations allow sizes and shapes to be determined with kilometre accuracy, and provide the characteristics of the occulting object and its vicinity. Aims. Using stellar occultations observed between 2017 and 2020, our aim is to constrain the physical parameters of Chariklo and its rings. We also determine the structure of the rings, and obtain precise astrometrical positions of Chariklo. Methods. We predicted and organised several observational campaigns of stellar occultations by Chariklo. Occultation light curves were measured from the datasets, from which ingress and egress times, and the ring widths and opacity values were obtained. These measurements, combined with results from previous works, allow us to obtain significant constraints on Chariklo's shape and ring structure. Results. We characterise Chariklo's ring system (C1R and C2R), and obtain radii and pole orientations that are consistent with, but more accurate than, results from previous occultations. We confirm the detection of W-shaped structures within C1R and an evident variation in radial width. The observed width ranges between 4.8 and 9.1 km with a mean value of 6.5 km. One dual observation (visible and red) does not reveal any differences in the C1R opacity profiles, indicating a ring particle size larger than a few microns. The C1R ring eccentricity is found to be smaller than 0.022 (3σ), and its width variations may indicate an eccentricity higher than ~0.005. We fit a tri-axial shape to Chariklo's detections over 11 occultations, and determine that Chariklo is consistent with an ellipsoid with semi-axes of 143.8-1.5+1.4, 135.2-2.8+1.4, and 99.1-2.7+5.4 km. Ultimately, we provided seven astrometric positions at a milliarcsecond accuracy level, based on Gaia EDR3, and use it to improve Chariklo's ephemeris. © B. E. Morgado et al. 2021., This work was carried out within the “Lucky Star” umbrella that agglomerates the efforts of the Paris, Granada and Rio teams, which is funded by the European Research Council under the European Community’s H2020 (ERC Grant Agreement No. 669416). This research made use of SORA, a python package for stellar occultations reduction and analysis, developed with the support of ERC Lucky Star and LIneA/Brazil, within the collaboration Rio-Paris-Granada teams. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Part of this research is suported by INCT do e-Universo, Brazil (CNPQ grants 465376/2014-2). Based in part on observations made at the Laboratório Nacional de Astrofísica (LNA), Itajubá-MG, Brazil. The data include observations taken by the MiNDSTEp team at the Danish 1.54 m telescope at ESO’s La Silla observatory” and “UGJ acknowledges funding from the European Union H2020-MSCA-ITN-2019 under grant no. 860470 (CHAMELEON) and from the Novo Nordisk Foundation Interdisciplinary Synergy Programme grant no. NNF19OC0057374. TRAPPIST-South is funded by the Belgian Fund for Scientific Research (Fond National de la Recherche Scientifique, FNRS) under the grant PDR T.0120.21. The authors acknowledge the use of Sonja Itting-Enke’s C14 telescope and the facilities at the Cuno Hoffmeister Memorial Observatory (CHMO). The following authors acknowledge the respective CNPq grants: BEM 150612/2020-6; FB-R 314772/2020-0; RV-M 304544/2017-f5, 401903/2016-8; JIBC 308150/2016-3 and 305917/2019-6; MA 427700/2018-3, 310683/2017-3, 473002/2013-2. G.B.R. acknowledges CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016 and CAPES-PRINT/UNESP grant 88887.571156/2020-00, MA FAPERJ grant E-26/111.488/2013 and ARGJr FAPESP grant 2018/11239-8. J.L.O., P.S.-S., R.D., and N.M. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709), from Spanish project AYA2017-89637-R, and from FEDER. P.S.-S. acknowledges financial support by the Spanish grant AYA-RTI2018-098657-J-I00 “LEO-SBNAF” (MCIU/AEI/FEDER, UE). E. Jehin is a Belgian FNRS Senior Research Associate. R.S. and O.C.W. acknowledge FAPESP grant 2016/24561-0 and CNPq grant 305210/2018-1. T.C.H. acknowledges financial support from the National Research Foundation (NRF; No. 2019R1I1A1A01059609).

HCN and its isomer HNC play an important role in molecular cloud chemistry and the formation of more complex molecules. We investigate here the impact of protostellar shocks on the HCN and HNC abundances from high-sensitivity IRAM 30m observations of the prototypical shock region L1157-B1 and the envelope of the associated Class 0 protostar, as a proxy for the pre-shock gas. The isotopologues H$^{12}$CN, HN$^{12}$C, H$^{13}$CN, HN$^{13}$C, HC$^{15}$N, H$^{15}$NC, DCN and DNC were all detected towards both regions. Abundances and excitation conditions were obtained from radiative transfer analysis of molecular line emission under the assumption of Local Thermodynamical Equilibrium. In the pre-shock gas, the abundances of the HCN and HNC isotopologues are similar to those encountered in dark clouds, with a HCN/HNC abundance ratio $\approx 1$ for all isotopologues. A strong D-enrichment (D/H$\approx 0.06$) is measured in the pre-shock gas. There is no evidence of $^{15}$N fractionation neither in the quiescent nor in the shocked gas. At the passage of the shock, the HCN and HNC abundances increase in the gas phase in different manners so that the HCN/HNC relative abundance ratio increases by a factor 20. The gas-grain chemical and shock model UCLCHEM allows us to reproduce the observed trends for a C-type shock with pre-shock density $n$(H)= $10^5$cm$^{-3}$ and shock velocity $V_s= 40$km/s. We conclude that the HCN/HNC variations across the shock are mainly caused by the sputtering of the grain mantle material in relation with the history of the grain ices., Comment: 14 pages, 7 figures. Accepted for publication in MNRAS