Search

HIP 9618 (HD 12572, TOI-1471, TIC 306263608) is a bright (G = 9.0 mag) solar analogue. TESS photometry revealed the star to have two candidate planets with radii of 3.9 ± 0.044 R (HIP 9618 b) and 3.343 ± 0.039 R (HIP 9618 c). While the 20.77291 d period of HIP 9618 b was measured unambiguously, HIP 9618 c showed only two transits separated by a 680-d gap in the time series, leaving many possibilities for the period. To solve this issue, CHEOPS performed targeted photometry of period aliases to attempt to recover the true period of planet c, and successfully determined the true period to be 52.56349 d. High-resolution spectroscopy with HARPS-N, SOPHIE, and CAFE revealed a mass of 10.0 ± 3.1M for HIP 9618 b, which, according to our interior structure models, corresponds to a 6.8 ± 1.4 per cent gas fraction. HIP 9618 c appears to have a lower mass than HIP 9618 b, with a 3-sigma upper limit of 50 d, opening the door for the atmospheric characterization of warm (Teq < 750 K) sub-Neptunes. ISSN:0035-8711 ISSN:1365-2966

We report the discovery and Doppler mass measurement of a 7.4-day 2.3-$R_\oplus$ mini-Neptune around a metal-poor K dwarf BD+29 2654 (TOI-2018). Based on a high-resolution Keck/HIRES spectrum, the Gaia parallax, and multi-wavelength photometry from the ultraviolet to the mid-infrared, we found that the host star has $T_{\text{eff}}=4174^{+34}_{-42}$ K, $\log{g}=4.62^{+0.02}_{-0.03}$, $[\text{Fe/H}]=-0.58\pm0.18$, $M_{\ast}=0.57\pm0.02~M_{\odot}$, and $R_{\ast}=0.62\pm0.01~R_{\odot}$. Precise Doppler measurements with Keck/HIRES revealed a planetary mass of $M_{\text{p}}=9.2\pm2.1~M_{\oplus}$ for TOI-2018 b. TOI-2018 b has a mass and radius that are consistent with an Earth-like core with a $\sim1\%$-by-mass hydrogen/helium envelope, or an ice-rock mixture. The mass of TOI-2018 b is close to the threshold for run-away accretion and hence giant planet formation. Such a threshold is predicted to be around 10$M_\oplus$ or lower for a low-metallicity (low-opacity) environment. If TOI-2018 b is a planetary core that failed to undergo run-away accretion, it may underline the reason why giant planets are rare around low-metallicity host stars (one possibility is their shorter disk lifetimes). With a K-band magnitude of 7.1, TOI-2018 b may be a suitable target for transmission spectroscopy with the James Webb Space Telescope. The system is also amenable to metastable Helium observation; the detection of a Helium exosphere would help distinguish between a H/He enveloped planet and a water world., Comment: 10 figures, 5 tables, accepted to AAS Journals

Funding: TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1. We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (∼200 mas yr−1), low metallicity ([Fe/H]≈−0.28) K-dwarf with a mass of 0.68 ± 0.05 M⊙ and a radius of 0.67 ± 0.01 R⊙. We obtain photometric follow-up observations with a variety of facilities, and we use these data-sets to determine that the inner planet, TOI-836 b, is a 1.70 ± 0.07 R⊕ super-Earth in a 3.82 day orbit, placing it directly within the so-called ‘radius valley’. The outer planet, TOI-836 c, is a 2.59 ± 0.09 R⊕ mini-Neptune in an 8.60 day orbit. Radial velocity measurements reveal that TOI-836 b has a mass of 4.5 ± 0.9 M⊕, while TOI-836 c has a mass of 9.6 ± 2.6 M⊕. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 minutes for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet. Publisher PDF

Despite the discovery of thousands of exoplanets, the mechanisms of planet formation and evolution have not been well tested with observations, mainly because the lack of a complete photometric and spectroscopic characterization of young planets, which presents a big challenge due to the high stellar activity of young stars. By determining the masses of young exoplanets, we can establish their composition, and investigate their evolution with age. For these observations, we can deduce if they were formed without gas (rocky planets) from their origin, or if they are born as small gaseous planets that lose their atmosphere rapidly (~tens of Myr) by photoevaporation (Murray-Clay et al. 2019) or slowly (~1 Gyr) by core-powered mass loss (Ginzburg et al. 2018). HD63433 is a very bright and fast rotating (6.46 days) solar-type star of the young (~400Myr) Ursa Major moving group hosting two transiting mini-Neptune-size exoplanets (Mann et al. 2020) with orbital periods of 7.11 (HD63433 b) and 20.55 (HD63433 c) days. We have collected 150 Radial Velocity (RV) measurements of HD63433 with CARMENES spectrograph over 1.4 years to determine the mass of the planets (Mallorquín et al. 2022, in prep). We have jointly modeled the transits, the keplerian planetary signal, and stellar activity with Gaussian Processes combining the TESS photometry and the CARMENES RV dataset. Our results reveal that the outer planet is detected in the CARMENES time series with an amplitude of 4.1+-1.0 m/s at the level of 4-sigma, which correspond to an absolute mass of Mp=17.4+-4.3 mass of the Earth for HD63433 c, making it the smallest planet with a robust mass determination at young ages. We report an upper limit of Mp

CHOCOLATE is a novel Chromatic Line-Profile Tomography technique that has been recently developed and presented to the community as an alternative approach for recovering the broadband transmission spectrum of transiting exoplanets from high-resolution spectroscopy. This methodology is based on the spectral line-profile distortions produced by a transiting planet, which can be assessed in the Cross Correlation Functions (CCFs) of the spectra. In this poster, we show the transmission spectrum obtained for HD209458b using CHOCOLATE methodology and ESPRESSO data.

Ground-based transit observations are affected by both telluric absorption and instrumental systematics. To account for these effects, a better understanding of the impact of different data analyses is needed to improve the accuracy of the retrieved transmission spectra. We propose validating ground-based low-resolution transmission spectroscopy using transiting white dwarfs. The advantage here is that we know beforehand what the final transmission spectrum should be: a featureless flat spectrum. We analyzed two transiting white dwarfs analogous to hot Jupiters. We used various noise models to account for the systematic noise in their spectroscopic light curves following common procedures of transmission spectroscopy analyses. We compared the derived transmission spectra with the broadband transit depth to determine whether there are any artificial offsets or spectral features arising from light-curve fitting. The results show a strong model dependence, and the transmission spectra exhibit considerable discrepancies when they are computed with different noise models, different reference stars, and different common-mode removal methods. Nonetheless, we can still derive relatively accurate transmission spectra based on a Bayesian model comparison. With current ground-based instrumentation, the systematics in transit light curves can easily contaminate a transmission spectrum, introducing a general offset or some spurious spectral features and thus leading to a biased interpretation on the planetary atmosphere. Therefore, it is necessary to determine the dependence of results on the adopted noise model through model comparison. The model inferences should be examined through multiple observations and different instruments. (Abridged), Comment: Accepted for pulication in A&A, 18 pages, 9 figures

Full list of authors: Wilson, Thomas G.; Goffo, Elisa; Alibert, Yann; Gandolfi, Davide; Bonfanti, Andrea; Persson, Carina M.; Collier Cameron, Andrew; Fridlund, Malcolm; Fossati, Luca; Korth, Judith; Benz, Willy; Deline, Adrien; Florén, Hans-Gustav; Guterman, Pascal; Adibekyan, Vardan; Hooton, Matthew J.; Hoyer, Sergio; Leleu, Adrien; Mustill, Alexander James; Salmon, Sébastien; Sousa, Sérgio G.; Suarez, Olga; Abe, Lyu; Agabi, Abdelkrim; Alonso, Roi; Anglada, Guillem; Asquier, Joel; Bárczy, Tamas; Barrado Navascues, David; Barros, Susana C. C.; Baumjohann, Wolfgang; Beck, Mathias; Beck, Thomas; Billot, Nicolas; Bonfils, Xavier; Brandeker, Alexis; Broeg, Christopher; Bryant, Edward M.; Burleigh, Matthew R.; Buttu, Marco; Cabrera, Juan; Charnoz, Sébastien; Ciardi, David R.; Cloutier, Ryan; Cochran, William D.; Collins, Karen A.; Colón, Knicole D.; Crouzet, Nicolas; Csizmadia, Szilard; Davies, Melvyn B.; Deleuil, Magali; Delrez, Laetitia; Demangeon, Olivier; Demory, Brice-Olivier; Dragomir, Diana; Dransfield, Georgina; Ehrenreich, David; Erikson, Anders; Fortier, Andrea; Gan, Tianjun; Gill, Samuel; Gillon, Michaël; Gnilka, Crystal L.; Grieves, Nolan; Grziwa, Sascha; Güdel, Manuel; Guillot, Tristan; Haldemann, Jonas; Heng, Kevin; Horne, Keith; Howell, Steve B.; Isaak, Kate G.; Jenkins, Jon M.; Jensen, Eric L. N.; Kiss, Laszlo; Lacedelli, Gaia; Lam, Kristine; Laskar, Jacques; Latham, David W.; Lecavelier des Etangs, Alain; Lendl, Monika; Lester, Kathryn V.; Levine, Alan M.; Livingston, John; Lovis, Christophe; Luque, Rafael; Magrin, Demetrio; Marie-Sainte, Wenceslas; Maxted, Pierre F. L.; Mayo, Andrew W.; McLean, Brian; Mecina, Marko; Mékarnia, Djamel; Nascimbeni, Valerio; Nielsen, Louise D.; Olofsson, Göran; Osborn, Hugh P.; Osborne, Hannah L. M.; Ottensamer, Roland; Pagano, Isabella; Pallé, Enric; Peter, Gisbert; Piotto, Giampaolo; Pollacco, Don; Queloz, Didier; Ragazzoni, Roberto; Rando, Nicola; Rauer, Heike; Redfield, Seth; Ribas, Ignasi; Ricker, George R.; Rieder, Martin; Santos, Nuno C.; Scandariato, Gaetano; Schmider, François-Xavier; Schwarz, Richard P.; Scott, Nicholas J.; Seager, Sara; Ségransan, Damien; Serrano, Luisa Maria; Simon, Attila E.; Smith, Alexis M. S.; Steller, Manfred; Stockdale, Chris; Szabó, Gyula; Thomas, Nicolas; Ting, Eric B.; Triaud, Amaury H. M. J.; Udry, Stéphane; Van Eylen, Vincent; Van Grootel, Valérie; Vanderspek, Roland K.; Viotto, Valentina; Walton, Nicholas; Winn, Joshua N., We report the discovery and characterization of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in the Transiting Exoplanet Survey Satellite (TESS) photometry. To characterize the system, we performed and retrieved the CHaracterising ExOPlanets Satellite (CHEOPS), TESS, and ground-based photometry, the High Accuracy Radial velocity Planet Searcher (HARPS) high-resolution spectroscopy, and Gemini speckle imaging. We characterize the host star and determine Teff,⋆=4734±67K⁠, R⋆=0.726±0.007R⊙⁠, and M⋆=0.748±0.032M⊙⁠. We present a novel detrending method based on point spread function shape-change modelling and demonstrate its suitability to correct flux variations in CHEOPS data. We confirm the planetary nature of both bodies and find that TOI-1064 b has an orbital period of Pb = 6.44387 ± 0.00003 d, a radius of Rb = 2.59 ± 0.04 R⊕, and a mass of Mb=13.5+1.7−1.8 M⊕, whilst TOI-1064 c has an orbital period of Pc=12.22657+0.00005−0.00004 d, a radius of Rc = 2.65 ± 0.04 R⊕, and a 3σ upper mass limit of 8.5 M⊕. From the high-precision photometry we obtain radius uncertainties of ∼1.6 per cent, allowing us to conduct internal structure and atmospheric escape modelling. TOI-1064 b is one of the densest, well-characterized sub-Neptunes, with a tenuous atmosphere that can be explained by the loss of a primordial envelope following migration through the protoplanetary disc. It is likely that TOI-1064 c has an extended atmosphere due to the tentative low density, however further radial velocities are needed to confirm this scenario and the similar radii, different masses nature of this system. The high-precision data and modelling of TOI-1064 b are important for planets in this region of mass–radius space, and it allow us to identify a trend in bulk density–stellar metallicity for massive sub-Neptunes that may hint at the formation of this population of planets. © The Author(s) 2022., This study is based on observations made with ESO Telescopes at the La Silla Observatory under program ID 1102.C-0923. 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 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. Funding for the TESS mission is provided by NASA Science Mission Directorate. We acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. Part of this work was done using data taken by KESPRINT, an international consortium devoted to the characterization and research of exoplanets discovered with space-based missions (http://www.kesprint.science/). This work makes use of observations from the LCOGT network. Part of the LCOGT telescope time was granted by NOIRLab through the Mid-Scale Innovations Program (MSIP). MSIP is funded by NSF. This study is based on data collected under the NGTS project at the ESO La Silla Paranal Observatory. The NGTS facility is operated by the consortium institutes with support from the UK Science and Technology Facilities Council (STFC) projects ST/M001962/1 and ST/S002642/1. 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. This work makes use of observations from the ASTEP telescope. ASTEP benefited from the support of the French and Italian polar agencies IPEV and PNRA in the framework of the Concordia station program and from Idex UCAJEDI (ANR-15-IDEX-01). Some of the observations in the paper made use of the High-Resolution Imaging instrument Zorro. Zorro was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. Zorro was mounted on the Gemini-South telescope of the international Gemini Observatory, a program of NSF’s OIR Lab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (USA), National Research Council Canada (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1. YA and MJH acknowledge the support of the Swiss National Fund under grant 200020_172746. DG and LMS gratefully acknowledge financial support from the CRT Foundation under grant no. 2018.2323 ‘Gaseous or rocky? Unveiling the nature of small worlds’. DG, MF, XB, SC, and JL acknowledge their roles as ESA-appointed CHEOPS science team members. CMP, MF, JK, and AJM gratefully acknowledge the support of the Swedish National Space Agency (SNSA; DNR 65/19, 174/18, 2020-00104, and Career grant 120/19C). ADe and DE acknowledge support from the European Research Council (ERC) under the European Union’s Horizon 2020 Framework Programme (project fOURaCES; grant agreement no. 724427). ADe, ALe, and HO acknowledge support from the Swiss National Centre for Competence in Research ‘PlanetS’ and the Swiss National Science Foundation (SNSF). SH gratefully acknowledges CNES funding through the grant 837319. SES have received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Framework Programme (grant agreement no. 833925, project STAREX). SGS acknowledges support from FCT through FCT contract no. CEECIND/00826/2018 and POPH/FSE (EC). 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 Astrobiología (INTA-CSIC), and the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract no. 4000124370. SCCB and VA acknowledge support from FCT through FCT contracts no. IF/01312/2014/CP1215/CT0004 and IF/00650/2015/CP1273/CT0001, respectively. ABr was supported by the SNSA. This project was supported by the CNES. LD is an F.R.S.-FNRS Postdoctoral Researcher. 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. 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 & POCI-01-0145-FEDER-032113, PTDC/FIS-AST/28953/2017 & 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. B-OD acknowledges support from the Swiss National Science Foundation (PP00P2-190080). DD acknowledges support from the TESS Guest Investigator Program grant 80NSSC19K1727 and NASA Exoplanet Research Program grant 18-2XRP18_2-0136. MG is an F.R.S.-FNRS Senior Research Associate. 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. GL acknowledges support by CARIPARO Foundation, according to the agreement CARIPARO-Universitá degli Studi di Padova (Pratica no. 2018/0098). This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche. ML acknowledges support from the Swiss National Science Foundation under grant no. PCEFP2_194576. PFLM acknowledges support from STFC research grant number ST/M001040/1. LDN thanks the Swiss National Science Foundation for support under Early Postdoc. Mobility grant P2GEP2_200044. This work was also partially supported by a grant from the Simons Foundation (PI: Queloz, grant number 327127). IR 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. This project has been supported by the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, the MTA-ELTE Lendület Milky Way Research Group, and the City of Szombathely under agreement no. 67.177-21/2016. This research received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Framework Programme (grant agreement no. 803193/BEBOP), and from the Science and Technology Facilities Council (STFC; grant no. ST/S00193X/1). VVG is an F.R.S-FNRS Research Associate., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

Multi-bandphotometrictransitobservationsorlowresolutionspectroscopy(spectro-photometry)arenormallyusedtoretrievethebroadbandtransmissionspectraoftransitingexoplanetsinordertoassessthechemicalcompositionoftheiratmospheres.Here,wepresentanalternativeapproachforrecoveringthebroadbandtransmissionspectrausingchromaticDopplerTomography.Tovalidatethemethodandexamineitsperformance,weusednewobservationaldataobtainedwiththeESPRESSOinstrumenttoretrievethe transmissionspectraofthearchetypalhotJupiterHD209458b.Ourfindingsindicatethattherecoveredtransmissionspectrumisingoodagreementwiththeresultspresentedinpreviousstudies,whichuseddifferentmethodologiestoextractthespectrum.

Multi-band photometric transit observations or low resolution spectroscopy (spectro-photometry) are normally used to retrieve the broadband transmission spectra of transiting exoplanets in order to assess the chemical composition of their atmospheres. In this work, we present an alternative approach for recovering the broadband transmission spectra using chromatic Line-Profile Tomography. To validate the method and examine its performance, we used new observational data obtained with the ESPRESSO instruments to retrieve the transmission spectra of the archetypal hot Jupiter HD209458b. Our findings indicate that the recovered transmission spectrum is in good agreement with the results presented in previous studies, which used different methodologies to extract the spectrum.

TOI 1246 is one of only eight four-planet systems with measured masses and radii for all four planets. TESS observed this moderately bright K dwarf (V=11.6, K=9.9) for 12 sectors, and found four transiting planets. We collected 90 RV observations with Keck/HIRES and TNG/HARPS-N, many of which were contemporaneous with TESS photometry. We refit the photometry to refine planet radii, measure masses for all four planets, and find a surprising range of masses and densities. This system is brighter 93% of other four planet systems, and is a particularly interesting testing ground for mass loss and formation hypotheses due to the high planet multiplicity and varied planet masses., {"references":["Tamayo, Daniel et al. (2020), arXiv:2007.06521"]}

One of the long-term goals of exoplanet science is the atmospheric characterization of dozens of small exoplanets in order to understand their diversity and search for habitable worlds and potential biosignatures. Achieving this goal requires a space mission of sufficient scale. We seek to quantify the exoplanet detection performance of a space-based mid-infrared nulling interferometer that measures the thermal emission of exoplanets. For this, we have developed an instrument simulator that considers all major astrophysical noise sources and coupled it with Monte Carlo simulations of a synthetic exoplanet population around main-sequence stars within 20 pc. This allows us to quantify the number (and types) of exoplanets that our mission concept could detect over a certain time period. Two different scenarios to distribute the observing time among the stellar targets are discussed and different apertures sizes and wavelength ranges are considered. Within a 2.5-year initial search phase, an interferometer consisting of four 2 m apertures covering a wavelength range between 4 and 18.5 μm could detect up to ~550 exoplanets with radii between 0.5 and 6 R⊕ with an integrated SNR≥7. At least ~160 of the detected exoplanets have radii ≤1.5 R⊕. Depending on the observing scenario, ~25-45 rocky exoplanets (objects with radii between 0.5 and 1.5 ⊕) orbiting within the empirical habitable zone (eHZ) of their host stars are among the detections. With four times 3.5 m aperture size, the total number of detections can increase to up to ~770, including ~60-80 rocky, eHZ planets. With four times 1 m aperture size, the maximum detection yield is ~315 exoplanets, including ≤20 rocky, eHZ planets. In terms of predicted detection yield, such a mission can compete with large single-aperture reflected light missions.

We report the discovery of an intermediate-mass transiting brown dwarf (BD), TOI-503b, from the TESS mission. TOI-503b is the first BD discovered by TESS, and it has circular orbit around a metallic-line A-type star with a period of P = 3.6772 ± 0.0001 days. The light curve from TESS indicates that TOI-503b transits its host star in a grazing manner, which limits the precision with which we measure the BD's radius . We obtained high-resolution spectroscopic observations with the FIES, Ondrejov, PARAS, Tautenburg, and TRES spectrographs, and measured the mass of TOI-503b to be M b = 53.7 ± 1.2 a radius of R = 1.70 ± 0.05R o, an effective temperature of T eff = 7650 ± 160 K, and a relatively high metallicity of 0.61 ± 0.07 dex. We used stellar isochrones to derive the age of the system to be ∼180 Myr, which places its age between that of RIK 72b (a ∼10 Myr old BD in the Upper Scorpius stellar association) and AD 3116b (a ∼600 Myr old BD in the Praesepe cluster). Given the difficulty in measuring the tidal interactions between BDs and their host stars, we cannot precisely say whether this BD formed in situ or has had its orbit circularized by its host star over the relatively short age of the system. Instead, we offer an examination of plausible values for the tidal quality factor for the star and BD. TOI-503b joins a growing number of known short-period, intermediate-mass BDs orbiting main-sequence stars, and is the second such BD known to transit an A star, after HATS-70b. With the growth in the population in this regime, the driest region in the BD desert is reforesting., J.Š. and P.K. would like to acknowledge the support from GACR international grant 17-01752J. J.Š. would like to acknowledge the support from source 116-09/260441, Institute of Theoretical Physics, Charles University in Prague, Czech Republic. J.K., S.G., M.P., S.C., A.P.H., H.R., M.E., and K.W.F. L. acknowledge support by Deutsche Forschungsgemeinschaft (DFG) grants PA525/18-1, PA525/19-1, PA525/20-1, HA 3279/12-1, and RA 714/14-1 within the DFG Schwerpunkt SPP 1992, Exploring the Diversity of Extrasolar Planets. S.C. acknowledges the Hungarian Scientific Research Fund (OTKA) Grant KH-130372. This work is partly supported by JSPS KAKENHI grant Nos. JP18H01265 and JP18H05439, and JST PRESTO grant No. JPMJPR1775. S.M. acknowledges support by the Spanish Ministry through the Ramon y Cajal fellowship number RYC-2015-17697. R.A.G. acknowledges the support from the PLATO/CNES grant. M.S. acknowledges the Postdoc@MUNI project CZ.02.2.69/0.0/0.0/16-027/0008360. S. M. acknowledges support from the ERC SPIRE 647383 grant. M.F., C.M.P., and I.G. gratefully acknowledge the support of the Swedish National Space Agency (DNR 163/16 and 174/18). K. G.S. acknowledges partial support from NASA grant 17-XRP17 2-0024. This paper includes data collected by the Kepler mission. Funding for the Kepler mission is provided by the NASA Science Mission directorate. Some of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofísica de Canarias. Also based in part on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO program P103.C-0449. T.W.C. would like to acknowledge the effort of the observers who acquired the ground-based photometry at FLWO, LCO, CHAT, and FLI as part of the TESS Follow-up Program. Thanks to Alex J. Mustill and Scott Gaudi for useful discussions. The PARAS spectrograph is fully funded and being supported by Physical Research Laboratory (PRL), which is part of Department of Space, Government of India. R.S. and A.C. would like to thank Director P.R.L. for his support and acknowledges the help from Vishal Shah and the Mount Abu Observatory staff at the time of observations. A.C. is grateful to Suvrath Mahadevan from Pennsylvania State University and Arpita Roy from Caltech, for their tremendous efforts in the development of the PARAS data pipeline.

For the first time in human history, we will soon be able to apply the scientific method to the question "Are We Alone?" The rapid advance of exoplanet discovery, planetary systems science, and telescope technology will soon allow scientists to search for life beyond our Solar System through direct observation of extrasolar planets. This endeavor will occur alongside searches for habitable environments and signs of life within our Solar System. While the searches are thematically related and will inform each other, they will require separate observational techniques. The search for life on exoplanets holds potential through the great diversity of worlds to be explored beyond our Solar System. However, there are also unique challenges related to the relatively limited data this search will obtain on any individual world. This white paper reviews the scientific community's ability to use data from future telescopes to search for life on exoplanets. This material summarizes products from the Exoplanet Biosignatures Workshop Without Walls (EBWWW). The EBWWW was constituted by a series of online and in person activities, with participation from the international exoplanet and astrobiology communities, to assess state of the science and future research needs for the remote detection of life on planets outside our Solar System., This is a white paper that was submitted to the National Academies of Sciences Study: Astrobiology Science Strategy for the Search for Life in the Universe

Linear polarization due to scattering processes can be used as a probe of the existence of atmospheric condensates in ultracool dwarfs. Models predict that the observed linear polarization increases with the degree of oblateness, which is inverse to the surface gravity. We aimed to measure optical linear polarization from a sample of six young brown dwarfs, with spectral types between M6 to L2, and cataloged previously as objects with low gravity using spectroscopy. These targets are believed to have dusty atmospheres as a consequence of their low gravity, therefore linearly polarized light is expected from these objects. Linear polarimetric data were collected in $I$ and $R$-band using CAFOS at the 2.2m telescope in Calar Alto Observatory. We obtained results of linear polarization in the I-band compatible with non polarization for all the objects, and similar results for the polarization degree in the R-band for all objects with the exception of 2M0422. For this object we find a linear polarization degree of 0.81+-0.18%. 2M0422 is 10 deg to the south of the Taurus star-forming region, thus, we suspect that its polarization is caused by the dust in the cloud in which 2M0422 might be embedded.

A recent study has suggested a link between the surface level diurnal temperature range (DTR) and variations in the cosmic ray (CR) flux. As the DTR is an effective proxy for cloud cover, this result supports the notion that widespread cloud changes may be induced by the CR flux. If confirmed, this would have significant implications for our understanding of natural climate forcings. Here, we perform a detailed investigation of the relationships between DTR and solar activity (total solar irradiance and the CR flux) from more than 60 years of NCEP/NCAR reanalysis data and observations from meteorological station data. We find no statistically significant evidence to suggest that the DTR is connected to either long- term solar periodicities (11 or 1.68-year) or short-term (daily timescale) fluctuations in solar activity, and we attribute previous reports on the contrary to an incorrect estimation of the statistical significance of the data. If a CR–DTR relationship exists, based on the estimated noise in DTR composites during Forbush decrease (FD) events, the DTR response would need to be larger than 0.03°C per 1% increase in the CR flux to be reliably detected. Compared with a much smaller rough estimate of −0.005°C per 1% increase in the CR flux expected if previous claims that FD events cause reductions in the cloud cover are valid, we conclude it is not possible to detect a solar related responses in station-based or reanalysis- based DTR data sets related to a hypothesized CR– cloud link, as potential signals would be drowned in noise.

The manuscript Svensmark et al (2012), hereafter referred to as SES12, continues the work begun in an earlier study by Svensmark et al. (2009), in an attempt to analyze the effects of Forbush Decrease (FD) events on cloud properties. The authors have focused on cloud parameters from the Moderate Resolution Imaging Spectroradiometer (MODIS) dataset, claiming that significant changes in a range of globally averaged MODIS cloud properties support the hypothesized link between changes in the galactic cosmic ray (GCR) flux and cloud cover. After a detailed and careful analysis of the MODIS cloud fraction data we find that the results presented in SES12 are statistically insignificant and their conclusions are unsupported by the data. We attribute the author’s significant results to a poor statistical handling of the data, and consequently recommend rejection of this work.

Póster elaborado para la European Geosciences Union General Assembly, celebrada en Viena del 3 al 8 de abril de 2011 Ministerio de Ciencia e Innovación. Proyecto NUCLIERSOL (CGL2010- 18546)

International audience; The science of extra-solar planets is one of the most rapidly changing areas of astrophysics and since 1995 the number of planets known has increased by almost two orders of magnitude. A combination of ground-based surveys and dedicated space missions has resulted in 560-plus planets being detected, and over 1200 that await confirmation. NASA's Kepler mission has opened up the possibility of discovering Earth-like planets in the habitable zone around some of the 100,000 stars it is surveying during its 3 to 4-year lifetime. The new ESA's Gaia mission is expected to discover thousands of new planets around stars within 200 parsecs of the Sun. The key challenge now is moving on from discovery, important though that remains, to characterisation: what are these planets actually like, and why are they as they are? In the past ten years, we have learned how to obtain the first spectra of exoplanets using transit transmission and emission spectroscopy. With the high stability of Spitzer, Hubble, and large ground-based telescopes the spectra of bright close-in massive planets can be obtained and species like water vapour, methane, carbon monoxide and dioxide have been detected. With transit science came the first tangible remote sensing of these planetary bodies and so one can start to extrapolate from what has been learnt from Solar System probes to what one might plan to learn about their faraway siblings. As we learn more about the atmospheres, surfaces and near-surfaces of these remote bodies, we will begin to build up a clearer picture of their construction, history and suitability for life. The Exoplanet Characterisation Observatory, EChO, will be the first dedicated mission to investigate the physics and chemistry of Exoplanetary Atmospheres. By characterising spectroscopically more bodies in different environments we will take detailed planetology out of the Solar System and into the Galaxy as a whole. EChO has now been selected by the European Space Agency to be assessed as one of four M3 mission candidates.

International audience; The science of extra-solar planets is one of the most rapidly changing areas of astrophysics and since 1995 the number of planets known has increased by almost two orders of magnitude. A combination of ground-based surveys and dedicated space missions has resulted in 560-plus planets being detected, and over 1200 that await confirmation. NASA's Kepler mission has opened up the possibility of discovering Earth-like planets in the habitable zone around some of the 100,000 stars it is surveying during its 3 to 4-year lifetime. The new ESA's Gaia mission is expected to discover thousands of new planets around stars within 200 parsecs of the Sun. The key challenge now is moving on from discovery, important though that remains, to characterisation: what are these planets actually like, and why are they as they are? In the past ten years, we have learned how to obtain the first spectra of exoplanets using transit transmission and emission spectroscopy. With the high stability of Spitzer, Hubble, and large ground-based telescopes the spectra of bright close-in massive planets can be obtained and species like water vapour, methane, carbon monoxide and dioxide have been detected. With transit science came the first tangible remote sensing of these planetary bodies and so one can start to extrapolate from what has been learnt from Solar System probes to what one might plan to learn about their faraway siblings. As we learn more about the atmospheres, surfaces and near-surfaces of these remote bodies, we will begin to build up a clearer picture of their construction, history and suitability for life. The Exoplanet Characterisation Observatory, EChO, will be the first dedicated mission to investigate the physics and chemistry of Exoplanetary Atmospheres. By characterising spectroscopically more bodies in different environments we will take detailed planetology out of the Solar System and into the Galaxy as a whole. EChO has now been selected by the European Space Agency to be assessed as one of four M3 mission candidates.

One of the long-term goals of exoplanet science is the atmospheric characterization of dozens of small exoplanets in order to understand their diversity and search for habitable worlds and potential biosignatures. Achieving this goal requires a space mission of sufficient scale. We seek to quantify the exoplanet detection performance of a space-based mid-infrared nulling interferometer that measures the thermal emission of exoplanets. For this, we have developed an instrument simulator that considers all major astrophysical noise sources and coupled it with Monte Carlo simulations of a synthetic exoplanet population around main-sequence stars within 20 pc. This allows us to quantify the number (and types) of exoplanets that our mission concept could detect over a certain time period. Two different scenarios to distribute the observing time among the stellar targets are discussed and different apertures sizes and wavelength ranges are considered. Within a 2.5-year initial search phase, an interferometer consisting of four 2 m apertures covering a wavelength range between 4 and 18.5 μm could detect up to ~550 exoplanets with radii between 0.5 and 6 R⊕ with an integrated SNR≥7. At least ~160 of the detected exoplanets have radii ≤1.5 R⊕. Depending on the observing scenario, ~25-45 rocky exoplanets (objects with radii between 0.5 and 1.5 ⊕) orbiting within the empirical habitable zone (eHZ) of their host stars are among the detections. With four times 3.5 m aperture size, the total number of detections can increase to up to ~770, including ~60-80 rocky, eHZ planets. With four times 1 m aperture size, the maximum detection yield is ~315 exoplanets, including ≤20 rocky, eHZ planets. In terms of predicted detection yield, such a mission can compete with large single-aperture reflected light missions., arXiv

La exoplanetolog´ıa es a d´ıa de hoy una rama consolidada de la astrof´ısica con m´as de 4 000 exoplanetas descubiertos. Por eso, pr´oximas misiones como CHEOPS se centrar´an en observar planetas ya descubiertos, mejorando el conocimiento que tenemos sobre ellos. Pero por otra parte, hay que determinar cu´ales son los mejores candidatos para futuros estudios, especialmente para el estudio de sus atm´osferas. Aqu´ı es donde entra en juego Transiting Exoplanet Survey Satellite (TESS). TESS es un telescopio espacial que desde abril de 2018 orbita la Tierra y tiene como misi´on observar todo el cielo durante dos a˜nos, distribuido en sectores y cada uno durante 27 d´ıas. Tiene como objetivo detectar planetas alrededor de las estrellas m´as brillantes y cercanas que son las id´oneas para futuras observaciones, ya sean fotom´etricas o espectrosc´opicas, desde tierra o el espacio, para caracterizar en detalle sus propiedades e incluso sus atm´osferas. El m´etodo de detecci´on que utiliza el telescopio espacial TESS es el de tr´ansito. Cuando el planeta pasa enfrente de la estrella, el brillo que se recibe disminuye levemente, produciendo un tr´ansito o eclipse. Cuando se registra la evoluci´on del brillo de la estrella con el tiempo, lo que se denomina curva de luz, permite detectar estos tr´ansitos que se repiten de forma peri´odica. A partir de la curva de luz no solo se puede extraer el periodo de rotaci´on del planeta sino que a trav´es de la profundidad del tr´ansito, y conociendo el radio de la estrella, se puede determinar con gran precisi´on el radio del planeta (Ec. 1). Este m´etodo no permite la determinaci´on de la masa del planeta, para ello se utiliza conjuntamente el m´etodo de velocidades radiales. Este se ´ basa en medir por efecto Doppler el movimiento en la l´ınea de visi´on que produce el planeta sobre la estrella. Las oscilaciones en los valores de velocidad radial (RV) se pueden ajustar a modelos planetarios y as´ı obtener la semi-amplitud K de la se˜nal que permite calcular una cota m´ınima a la masa (Ec. 5). S´olo si se dispone de medidas fotom´etricas, se puede conocer la inclinaci´on de la orbita y as´ı conocer el valor exacto de la masa del planeta. Si se conoce la masa y el radio y por ende su densidad permite saber si es rocoso o gaseoso y aumentar el conocimiento sobre el nuevo planeta. En este trabajo se han combinado los datos fotom´etricos de TESS con medidas de RV de archivo. El paso previo al flujo de trabajo que realic´e en cada sector de TESS fue la recopilaci´on de medidas de velocidades radiales. As´ı, pude crear una base de datos de unas 290 000 observaciones de casi cinco mil estrellas observadas con HARPS, HIRES o HARPS-N, espectr´ografos de alta resoluci´on y estabilidad. Entonces busqu´e en qu´e sectores estas estrellas ser´ıan observadas por TESS y as´ı, para cada sector, conocer cu´ales eran los posibles candidatos a albergar exoplanetas. El flujo de trabajo para analizar cada sector fue el mismo. Unos d´ıas antes de la publicaci´on de los datos fotom´etricos hago un periodograma generalizado de Lomb-Scargle (GLS) de las RV de las estrellas que se observaran. As´ı se ve si hay periodicidades en los datos que puedan ser debidas a un exoplaneta que orbita la estrella. Este an´alisis permite hacer una primera criba de las estrellas que ya tienen planetas descubiertos y donde por tanto no ser´ıa raro encontrar tr´ansitos en sus curvas de luz. Una vez est´an disponibles los datos del sector, obtengo las curvas de luz mediante la herramienta TESScut utilizando el c´odigo de Python tesseract. Estas se analizan con el algoritmo ´ Transit Least Squares (TLS) en busca de tr´ansitos. En unos minutos se pueden revisar visualmente los resultados de todas las estrellas analizadas con TLS para ver si alguna tiene eclipses. El problema es que todo este proceso se aplica de forma generalizada y puede ser que alguna pase inadvertida y no se detecte. Por esto, despu´es de cada sector compruebo la lista de objetos de inter´es de TESS o TOIs. Uno de los equipos de TESS del MIT se encarga de buscar tr´ansitos en todas las estrellas del sector y alerta de las que encuentra que tienen eventos similares a los de tr´ansitos planetarios. Si se da que para alguna de las estrellas que tengo velocidades radiales se encuentran tr´ansitos, entonces realizo un an´alisis m´as en detalle de sus datos utilizando la librer´ıa de Python juliet. juliet permite hacer ajustes de fotometr´ıa, RV o ambos a la vez de modelos planetarios. Adem´as, calcula la evidencia bayesiana del modelo que permite una comparaci´on entre los modelos explorados. En los sectores analizados en este trabajo, que fueron del 17 al 23, TESS encontr´o 356 nuevos candidatos de los cuales s´olo de 3 dispon´ıa de velocidades radiales en los archivos. Los detalles del n´umero de estrellas analizadas se muestran en la Tabla 2. As´ı, los resultados que se presentan en el trabajo son el estudio y caracterizaci´on de los candidatos a planetas TOI 1718, 1827 y 1611. TOI 1718 es una estrella que se observ´o durante el Sector 20 y de la que se alertaron tr´ansitos con un per´ıodo de 5.58 d´ıas y que corresponder´ıan a un planeta con un radio de „4RC. La estrella estaba en la base de datos porque HIRES la observ´o 3 veces, pero la cantidad de medidas es insuficiente para calcular bien el GLS. Busqu´e m´as medidas en otros archivos pero no obtuve resultados ´utilies. Por esto propuse observarla con HARPS-N pero las condiciones meteorol´ogicas adversas lo impidieron. Sin m´as medidas que la fotometr´ıa de TESS no se puede confirmar el descubrimiento de este planeta, aunque por la consistencia de la profundidad de los tr´ansitos y la forma de ´estos no da indicios de que sea un falso positivo. El resultado del an´alisis de la curva de luz con juliet, mostrado en Fig. 3, sugiere la presencia de un planeta alrededor de TOI 1718 con un radio de 4.04`0.09 ´0.07RC. TOI 1827 es una enana roja que se observ´o durante el Sector 23 y se detectaron tr´ansitos cada 1.46 d´ıas correspondientes a un planeta de 1.3RC. En este caso dispongo de 12 medidas de HARPS y 62 de HIRES, cuyo an´alisis no muestra ninguna se˜nal significativa en el GLS. El an´alisis conjunto de RV y fotometr´ıa permite obtener par´ametros fotom´etricos consistentes con los alertados, y con menores errores, pero debido a la precisi´on de las RVs las incertidumbres en la masa del planeta son mayores. El ajuste con juliet confirma la presencia de una super-Tierra de 1.39`0.06 ´0.05RC y 1.2˘0.4MC. Con observaciones no p´ublicas del espectr´ografo CARMENES se ha obtenido de forma independiente un valor para K mayor al l´ımite superior que obtengo. TOI 1611 es el principal resultado de este trabajo. Fue observada durante los Sectores 18, 19 y 20 y se alert´o de un candidato con un periodo de 16.2 d´ıas y un radio de 2.5RC. Originalmente solo dispon´ıa de 6 RV de HIRES pero debido a la colaboraci´on con otro grupo de investigaci´on, que tambi´en report´o su descubrimiento, al final obtuve 67 medidas tomadas con el espectr´ografo SOPHIE. Los GLS de las RVs muestran un pico a 16.2 d´ıas confirmando la presencia del planeta. A parte, presentan varios picos significativos a 27, 32 y 35 d´ıas para los que despu´es de un largo an´alisis no pude determinar con certeza su naturaleza. Los par´ametros del planeta se extrajeron del an´alisis conjunto de las RV y fotometr´ıa con juliet utilizando un modelo de 1 planeta y con procesos gaussianos (GP) para explicar las sistem´aticas en las RVs. As´ı se pudo confirmar y caracterizar el planeta determinando una masa de 19˘4MC y un radio de 2.13`0.09 ´0.07RC. TOI 1611b es un planeta sub-neptuniano rocoso con una composici´on similar al de la Tierra, seg´un se extrae de Fig. 15. Los resultados del an´alisis de este planeta formar´an parte de un art´ıculo cient´ıfico en la revista Astronomy & Astrophysics del que participo como segundo autor.

We report the discovery of a Neptune-like planet (LP 714-47 b, P = 4.05204 d, mb = 30.8 ± 1.5Mpdbl, Rb = 4.7 ± 0.3 Rpdbl) located in the "hot Neptune desert". Confirmation of the TESS Object of Interest (TOI 442.01) was achieved with radial-velocity follow-up using CARMENES, ESPRESSO, HIRES, iSHELL, and PFS, as well as from photometric data using TESS, Spitzer, and ground-based photometry from MuSCAT2, TRAPPIST-South, MONET-South, the George Mason University telescope, the Las Cumbres Observatory Global Telescope network, the El Sauce telescope, the TÜBITAK National Observatory, the University of Louisville Manner Telescope, and WASP-South. We also present high-spatial resolution adaptive optics imaging with the Gemini Near-Infrared Imager. The low uncertainties in the mass and radius determination place LP 714-47 b among physically well-characterised planets, allowing for a meaningful comparison with planet structure models. The host star LP 714-47 is a slowly rotating early M dwarf (Teff = 3950 ± 51 K) with a mass of 0.59 ± 0.02Mpdbl and a radius of 0.58 ± 0.02Rpdbl. From long-term photometric monitoring and spectroscopic activity indicators, we determine a stellar rotation period of about 33 d. The stellar activity is also manifested as correlated noise in the radial-velocity data. In the power spectrum of the radial-velocity data, we detect a second signal with a period of 16 days in addition to the four-day signal of the planet. This could be shown to be a harmonic of the stellar rotation period or the signal of a second planet. It may be possible to tell the difference once more TESS data and radial-velocity data are obtained. © ESO 2020., CARMENES is an instrument for the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Institut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 "Blue Planets around Red Stars", the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia. Based on data from the CARMENES data archive at CAB (INTA-CSIC). We acknowledge the use of public TESS Alert data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. Some of the observations in the paper made use of the High-Resolution Imaging instrument Zorro. Zorro was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. Zorro was mounted on the Gemini South telescope of the international Gemini Observatory, a program of NSF's OIR Lab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. on behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigacion y Desarrollo (Chile), Ministerio de Ciencia, Tecnologia e Innovacion (Argentina), Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). This work makes use of observations from the LCOGT network. This article is based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sanchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. This paper is also based on observations made in the Observatorios de Canarias del IAC with the Nordic Optical Telescope operated on the island of La Palma by NOTSA in the Observatorio del Roque de los Muchachos. Data were partly obtained with the MONET/South telescope of the MOnitoring NEtwork of Telescopes, funded by the Alfried Krupp von Bohlen und Halbach Foundation, Essen, and operated by the Georg-August-Universitat Gottingen, the McDonald Observatory of the University of Texas at Austin, and the South African Astronomical Observatory. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This research made use of Lightkurve, a Python package for Kepler and TESS data analysis (Lightkurve Collaboration 2018). We acknowledge financial support from the Spanish Agencia Estatal de Investigacion of the Ministerio de Ciencia, Innovacion y Universidades and the European FEDER/ERF funds through projects AYA2015-69350-C3-2-P, PGC2018098153-B-C31/C33, AYA2016-79425-C3-1/2/3-P, AYA2018-84089, BES-2017080769, ESP2016-80435-C2-1/2-R, ESP2017-87676-C5-1/2/5-R, Instituto de Astrofisica de Andalucia (SEV-2017-0709), the Generalitat de Catalunya through CERCA programme, the UK Science and Technology Facilities Council through grant ST/P000592/1, the JSPS KAKENHI through grants 17H04574, JP18H01265, and 18H05439, and the JST PRESTO through grant JPMJPR1775, the "la Caixa" INPhINIT Fellowship Grant LCF/BQ/IN17/11620033 for Doctoral studies at Spanish Research Centres of Excellence, V.M.P. acknowledges support from NASA Grant NNX17AG24G, Support for this work was provided to J.K.T. by NASA through Hubble Fellowship grant HST-HF2-51399.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation. TRAPPIST is funded by the Belgian Fund for Scientific Research (Fond National de la Recherche Scientifique, FNRS) under the grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Foundation (SNF). M.G. and E.J. are FNRS Senior Research Associates. S.D. acknowledges support from the Deutsche Forschungsgemeinschaft under Research Unit FOR2544 "Blue Planets around Red Stars", project no. RE 281/32-1. M.Z. acknowledges support from the Deutsche Forschungsgemeinschaft under DFG RE 1664/12-1 and Research Unit FOR2544 "Blue Planets around Red Stars", project no. RE 1664/14-1. M.S. was supported by the DFG Research Unit FOR2544 "Blue Planets around Red Stars", project no. RE 2694/4-1. I.J.M.C. and E.M. acknowledge support from the National Science Foundation through grant AST-1824644. B.B. thanks the European Research Council (ERC Starting Grant 757 448-PAMDORA) for their financial support. D.D. acknowledges support from NASA through Caltech/JPL grant RSA-1006130 and through the TESS Guest Investigator Program Grant 80NSSC19K1727. P.P. acknowledges support from NASA (16-APROBES16-0020 and the Exoplanet Exploration Program) and the National Science Foundation (Astronomy and Astrophysics grant 1716202), the Mt Cuba Astronomical Foundation, and George Mason University start-up and instructional equipment funds. The NASA Infrared Telescope Facility is operated by the University of Hawaii under contract NNH14CK55B with the National Aeronautics and Space Administration. M.R.K is supported by the NSF Graduate Research Fellowship, grant No. DGE 1 339 067. M.Y. and H.V.S. thank to TUB.ITAK for a partial support in using T100 telescope with project number 19AT100-1474. J.N.W. thanks the Heising-Simons Foundation for support. D.H. acknowledges support from the Alfred P. Sloan Foundation, the National Aeronautics and Space Administration (80NSSC18K1585, 80NSSC19K0379), and the National Science Foundation (AST-1 717 000). T.D. acknowledges support from MIT's Kavli Institute as a Kavli postdoctoral fellow. This work made use of tpfplotter (developed by J. Lillo-Box, which also made use of the python packages astropy, lightkurve, matplotlib and numpy. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). The authors wish to recognise and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Finally, we thank the referee for detailed and helpful comments.

Dynamical histories of planetary systems, as well as atmospheric evolution of highly irradiated planets, can be studied by characterizing the ultra-short-period planet population, which the TESS mission is particularly well suited to discover. Here, we report on the follow-up of a transit signal detected in the TESS sector 19 photometric time series of the M3.0 V star TOI-1685. We confirm the planetary nature of the transit signal, which has a period of Pb = 0.6691403+0.0000023-0.0000021 d, using precise radial velocity measurements taken with the CARMENES spectrograph. From the joint photometry and radial velocity analysis, we estimate the following parameters for TOI-1685 b: a mass of Mb = 3.78+0.63- 0.63 M⊕, a radius of Rb = 1.70+0.07- 0.07 R⊕, which together result in a bulk density of ρb = 4.21+0.95-0.82 g/cm3, and an equilibrium temperature of Teq = 1069 +16-16 K. TOI-1685 b is the least dense ultra-short period planet around an M dwarf known to date. TOI-1685 b is also one of the hottest transiting super-Earth planets with accurate dynamical mass measurements, which makes it a particularly attractive target for thermal emission spectroscopy. Additionally, we report with moderate evidence a further non-transiting planet candidate in the system, TOI-1685[c], with an orbital period of Pc = 9.02+0.10- 0.12 d., {"references":["Espinoza et al. 2019, adsurl: https://ui.adsabs.harvard.edu/abs/2019MNRAS.490.2262E","Zeng et al. 2019, adsurl:https://ui.adsabs.harvard.edu/abs/2019PNAS..116.9723Z","Zeng et al. 2016, adsurl: http://adsabs.harvard.edu/abs/2016ApJ...819..127Z","Southworth, J. 2011, adsurl: http://adsabs.harvard.edu/abs/2011MNRAS.417.2166S","Martínez-Rodríguez et al. 2019, adsurl: https://ui.adsabs.harvard.edu/abs/2019ApJ...887..261M"]}

The thermal emission received from a planet is a key to characterize the physical and chemical properties of its atmosphere. The spectral resolution, and therefore the spectral characterization that we can achieve for extrasolar planets is unfortunately very limited in particular for terrestrial planets. In this thesis, we study the possibility to characterize an Earth-like exoplanet by the analysis of the broadband infrared emission variability. The apparent thermal emission is indeed modulated by the seasons, the rotation of the planet, the motion and variability of atmospheric patterns and clouds, the orbital phase, and even the presence of a moon. As a reference case, we have studied the thermal emission of the Earth seen as a distant point-source, as well as the variability and the dependency of the signal on the observation geometry. We have modeled the emission of the Earth using data derived from observations and data produced by a General Circulation Models (GCMs), comparing both types of data in order to validate our simulations.As a second part of our work, we have used the GCM to model Earth-like planets that differ from the Earth by a few parameters such as different rotation rates (including tidally-locked planets), a planetary surface completely covered by ice or water, different obliquities and eccentricities. For all these virtual planets, we have studied the climate derived from the physical properties and the photometric infrared signal associated with them.The last part of the thesis is a preliminary work that no longer consider the bolometric emission but the signal from narrow spectral bands, thanks to a new generation of GCMs. Because each band probes a specific level in the atmosphere, studying how the low resolution spectrum of the planets varies by comparing the photometric variabilities between bands, we can study the dynamics, composition, distribution and evolution of the atmosphere of the planet, which it opens a yet unexplored field for the characterization of exoplanets.; Le signal thermique d'une exoplanète tellurique est une clé pour caractériser les propriétés physiques et chimiques de son atmosphère. La résolution spectrale, et donc la caractérisation spectrale que nous pouvons réaliser des planètes extrasolaires, est malheureusement très limité, en particulier pour les planètes similaires à la Terre. Dans cette thèse, j'ai étudié la possibilité de caractériser des exoplanètes telluriques par l'analyse de la variabilité de son émission infrarouge. L'émission thermique apparente est en effet modulée par les saisons, la rotation de la planète, le mouvement et la variabilité des nuages, la phase orbitale, et aussi par la présence des satellites naturels.Premièrement, nous avons étudié l' émission thermique de la Terre vue en tant que point-source distante, ainsi que la variabilité et la dépendance du signal de la géométrie d'observation. J'ai modélisé l'émission de la Terre à l'aide des données satellitaires et des données produites par des modèles de circulation général (GCMs) du Laboratoire de Météorologie Dynamique de Paris (LMD), en comparant les deux types de données afin de valider les simulations.Pendant la deuxième partie de mon travail, j'ai utilisé des donnés du GCM pour modéliser des planètes telluriques qui diffèrent de la Terre par seulement un ou deux paramètres tels que: la vitesse de rotation (y compris des planètes synchrones), une surface planétaire entièrement recouverte par la glace ou de l'eau, l'obliquité de l'axe de rotation ou l'excentricité de l'orbite. Pour toutes ces planètes virtuelles, j'ai étudié le climat, déduit les propriétés physiques de la planète, et produit et analysé les signaux intégrés associés à différentes géométries d'observation.La dernière partie de la thèse est un travail préliminaire qui consiste en ne plus considérer l'émission bolométrique mais le signal de bandes spectrales étroites, grâce à une nouvelle génération de GCM. Parce que chaque bande explore un niveau spécifique dans l'atmosphère, l'étude de la variation du spectre en comparant les variabilités photométriques entre les bandes, permet d'étudier la dynamique, la composition, la distribution et l'évolution de l'atmosphère de la planète, ce qui ouvre un champ encore inexploré pour la caractérisation des exoplanètes.