Search

Aims. We report the confirmation of a new transiting exoplanet orbiting the star TOI-5076. Methods. We present our vetting procedure and follow-up observations which led to the confirmation of the exoplanet TOI-5076b. In particular, we employed high-precision TESS photometry, high-angular-resolution imaging from several telescopes, and high-precision radial velocities from HARPS-N. Results. From the HARPS-N spectroscopy, we determined the spectroscopic parameters of the host star: Teff = (5070±143) K, log 푔 = (4.6±0.3), [Fe/H] = (+0.20±0.08), and [α/Fe] = 0.05±0.06. The transiting planet is a warm sub-Neptune with a mass mp = (16±2) M⊙, a radius rp =(3.2±0.l) R⊙ yielding a density ρp = (2.8±0.5) g cm−3. It revolves around its star approximately every 23.445 days. Conclusions. The host star is a metal-rich, K2V dwarf, located at about 82 pc from the Sun with a radius of R⋆ = (0.78±0.01) R⊙ and a mass of M⋆ = (0.80±0.07) M⊙. It forms a common proper motion pair with an M-dwarf companion star located at a projected separation of 2178 au. The chemical analysis of the host-star and the Galactic-space velocities indicate that TOI-5076 belongs to the old population of thin-to-thick-disk transition stars. The density of TOI-5076b suggests the presence of a large fraction by volume of volatiles overlying a massive core. We found that a circular orbit solution is marginally favored with respect to an eccentric orbit solution for TOI-5076b. [ABSTRACT FROM AUTHOR]

Context. Stellar activity is the most relevant types of astrophysical noise that affect the discovery and characterization of extrasolar planets. On the other hand, the amplitude of stellar activity could hint at an interaction between the star and a close-in giant planet. Progress has been made in recent years in understanding how to deal with stellar activity and search for observational evidence of star-planet interactions. Aims. The aim of this work is to characterize the chromospheric activity of stars hosting short-period exoplanets by studying the correlations between the chromospheric emission (CE) in the Ca II H&K and the planetary parameters. Methods. We measured CE in the Ca II H&K lines using more than 1900 high-resolution spectra of a sample composed of 76 targets, observed with the HARPS-N spectrograph between 2012 and 2020. We transformed the fluxes into bolometric- and photospheric-corrected chromospheric emission ratios, R′HK. Furthermore, we completed the sample of hosts digging for data in previous works. Stellar parameters Teff, B–V, and V were retrieved homogeneously from the Gaia DR3. Then, M★, R★, and ages were determined from isochrone fitting. We retrieved planetary data from the literature and catalogs. The search for correlations between the log(R′HK) and planetary parameters have been performed through both Spearman's rank and its statistics as well as the more sophisticated Gaussian mixture model method. Results. We found that the distribution of log(R′HK) for the transiting planet hosts is different from the distribution of field main-sequence and sub-giant stars. The log(R′HK) of planetary hosts is correlated with planetary parameters proportional to the planetary radius to the power of n (RPn, indicating a common origin for the correlations. The statistical analysis has also highlighted four clusters of host stars with different behavior in terms of their stellar activity with respect to the planetary surface gravity. Some of the host stars have a value of log(R′HK) that is lower than the basal level of activity for main sequence stars. The planets of these systems are very close to filling their Roche lobe, suggesting that they evaporate through hydrodynamic escape under the strong irradiation of the host star, creating shrouds that absorb the core of the chromospheric resonance lines. [ABSTRACT FROM AUTHOR]

We characterize twelve young stellar objects (YSOs) located in the Lupus I region, spatially overlapping with the Upper Centaurus Lupus (UCL) sub-stellar association. The aim of this study is to understand whether the Lupus I cloud has more members than what has been claimed so far in the literature and gain a deeper insight into the global properties of the region. We selected our targets using the Gaia DR2 catalog based on their consistent kinematic properties with the Lupus I bona fide members. In our sample of twelve YSOs observed by X-shooter, we identified ten Lupus I members. We could not determine the membership status of two of our targets, namely Gaia DR2 6014269268967059840 and 2MASS J15361110-3444473 due to technical issues. We found out that four of our targets are accretors, among them, 2MASS J15551027-3455045, with a mass of ∼0.03 M⊙, is one of the least massive accretors in the Lupus complex identified to date. Several of our targets (including accretors) are formed in situ and off-cloud with respect to the main filaments of Lupus I; hence, our study may hint that there are diffused populations of M dwarfs around Lupus I main filaments. In this context, we would like to emphasize that our kinematic analysis with Gaia catalogs played a key role in identifying the new members of the Lupus I cloud. [ABSTRACT FROM AUTHOR]

This is the first case of a patient with a histological diagnosis of RPF achieving complete remission of the disease after eradication of H. pylori infection. Lumbosacral spine magnetic resonance imaging showed periaortic tissue of uncertain significance at the L3 level, and computed tomography (CT) showed hypodense tissue surrounding the subrenal aorta for 8 cm. To rule out a malignant aetiology, endoscopic evaluation was performed. Retroperitoneal fibrosis (RPF), a rare disease characterized by fibroinflammatory tissue around the infrarenal portion of the abdominal aorta and iliac arteries, is classified into primary (or idiopathic) and secondary forms ([1]). [Extracted from the article]

I report the results of a new search for transiting planets on a set of 1.4 million light curves extracted from TESS Full Frame Images (FFIs) using the DIAmante pipeline. The data come from the first 2 yr of observations of TESS (Sectors 1–26) and the study is focused on a sample of FGKM dwarf and subgiant stars optimized for the search of transiting planets. The search was performed on the detrended and stitched multisector light curves applying the Box-fitting Least Squares algorithm and a Random Forest classifier. I present a catalogue of 1160 transiting planet candidates, among which 842 are novel discoveries. The median radius of the transiting bodies in the catalogue is 6.8 R⊕. The radii range from 0.8 R⊕ to 27.3R⊕, while the orbital periods range from 0.19 to 197.2 d with a median of 3.6 d. Each candidate is accompanied by a validation report and the corresponding DIAmante light curve. The material is available at CDS, on the ExoFOP website and on the DIAmante portal at MAST. [ABSTRACT FROM AUTHOR]

Aims. We present a novel method for studying the thermal emission of exoplanets as a function of orbital phase at very high spectral resolution, and use it to investigate the climate of the ultra-hot Jupiter KELT-9b. Methods. We combine three nights of HARPS-N and two nights of CARMENES optical spectra, covering orbital phases between quadratures (0.25 < φ < 0.75), when the planet shows its day-side hemisphere with different geometries. We co-add the signal of thousands of Fe I lines through cross-correlation, which we map to a likelihood function. We investigate the phase-dependence of two separate observable quantities, namely (i) the line depths of Fe I and (ii) their Doppler shifts, introducing a new method that exploits the very high spectral resolution of our observations. Results. We confirm a previous detection of Fe I emission, and demonstrate a precision of 0.5 km s−1 on the orbital properties of KELT-9b when combining all nights of observations. By studying the phase-resolved Doppler shift of Fe I lines, we detect an anomaly in the planet's orbital radial velocity well-fitted with a slightly eccentric orbital solution (e = 0.016 ± 0.003, ω = 150−11+13°, 5σ preference). However, we argue that this anomaly is caused by atmospheric circulation patterns, and can be explained if neutral iron gas is advected by day-to-night atmospheric wind flows of the order of a few km s−1. We additionally show that the Fe I emission line depths are symmetric around the substellar point within 10° (2σ), possibly indicating the lack of a large hot-spot offset at the altitude probed by neutral iron emission lines. Finally, we do not obtain a significant preference for models with a strong phase-dependence of the Fe I emission line strength. We show that these results are qualitatively compatible with predictions from general circulation models (GCMs) for ultra-hot Jupiter planets. Conclusions. Very high-resolution spectroscopy phase curves are of sufficient sensitivity to reveal a phase dependence in both the line depths and their Doppler shifts throughout the orbit. They constitute an under-exploited treasure trove of information that is highly complementary to space-based phase curves obtained with HST and JWST, and open a new window onto the still poorly understood climate and atmospheric structure of the hottest planets known to date. [ABSTRACT FROM AUTHOR]

In this work, we present the analysis of 976 814 FGKM dwarf and subgiant stars in the Transiting Exoplanet Survey Telescope (TESS) full frame images (FFIs) of the Southern ecliptic hemisphere. We present a new pipeline, DIAmante, developed to extract optimized, multisector photometry from TESS FFIs and a classifier, based on the Random Forest technique, trained to discriminate plausible transiting planetary candidates from common false positives. A new statistical model was developed to provide the probability of correct identification of the source of variability. We restricted the planet search to the stars located in the least crowded regions of the sky and identified 396 transiting planetary candidates among which 252 are new detections. The candidates' radius distribution ranges between 1 R ⊕ and 2.6 R J with median value of 1 R J and the period distribution ranges between 0.25 and 105 d with median value of 3.8 d. The sample contains four long period candidates (P > 50 d), one of which is new, and 64 candidates with periods between 10 and 50 d (42 new ones). In the small planet radius domain (4 R < R ⊕), we found 39 candidates among which 15 are new detections. Additionally, we present 15 single transit events (14 new ones), a new candidate multiplanetary system, and a novel candidate around a known TOI. By using Gaia dynamical constraints, we found that 70 objects show evidence of binarity. We release a catalogue of the objects we analysed and the corresponding light curves and diagnostic figures through the MAST and ExoFOP portals. [ABSTRACT FROM AUTHOR]

The scope of the project 'A PSF-based Approach to TESS High Quality data Of Stellar clusters' (PATHOS) is the extraction and analysis of high-precision light curves of stars in stellar clusters and young associations for the identification of candidate exoplanets and variable stars. The cutting-edge tools used in this project allow us to measure the real flux of stars in dense fields, minimizing the effects due to contamination by neighbour sources. We extracted about 200 000 light curves of stars in 645 open clusters located in the Southern ecliptic hemisphere and observed by TESS during the first year of its mission. We searched for transiting signals and we found 33 objects of interest, 11 of which are strong candidate exoplanets. Because of the limited SNR, we did not find any Earth or super-Earth. We identified two Neptune-size planets orbiting stars with |$R_{\star }\lt 1.5\, \mathrm{\it R}_{\odot }$|⁠ , implying a frequency |$f_{\star }=1.34 \pm 0.95\, {{\ \rm per\ cent}}$|⁠ , consistent with the frequency around field stars. The seven Jupiter candidates around stars with |$R_{\star }\lt \, 1.5\, \mathrm{\it R}_{\odot }$| imply a frequency |$f_{\star }=0.19\pm 0.07\, {{\ \rm per\ cent}}$|⁠ , which is smaller than in the field. A more complete estimate of the survey completeness and false positive rate is needed to confirm these results. Light curves used in this work will be made available to the astronomical community on the Mikulski Archive for Space Telescope under the project PATHOS. [ABSTRACT FROM AUTHOR]

The TESS mission will survey ∼85  per cent of the sky, giving us the opportunity of extracting high-precision light curves of millions of stars, including stellar cluster members. In this work, we present our project 'A PSF-based Approach to TESS High quality data Of Stellar clusters' (PATHOS), aimed at searching and characterize candidate exoplanets and variable stars in stellar clusters using our innovative method for the extraction of high-precision light curves of stars located in crowded environments. Our technique of light-curve extraction involves the use of empirical point spread functions (PSFs), an input catalogue and neighbour-subtraction. The PSF-based approach allows us to minimize the dilution effects in crowded environments and to extract high-precision photometry for stars in the faint regime (G > 13). For this pilot project, we extracted, corrected, and analysed the light curves of 16 641 stars located in a dense region centred on the globular cluster 47 Tuc. We were able to reach the TESS magnitude T ∼ 16.5 with a photometric precision of |${\sim} 1{{\ \rm per\ cent}}$| on the 6.5-h time-scale; in the bright regime we were able to detect transits with depth of ∼34 parts per million. We searched for variables and candidate transiting exoplanets. Our pipeline detected one planetary candidate orbiting a main-sequence star in the Galactic field. We analysed the period–luminosity distribution for red-giant stars of 47 Tuc and the eclipsing binaries in the field. Light curves are uploaded on the Mikulski Archive for Space Telescopes under the project PATHOS. [ABSTRACT FROM AUTHOR]

Aims. The aim of this work is to search for planets around intermediate-mass stars in open clusters using data from an extensive survey with more than 15 yr of observations. Methods. We obtain high-precision radial velocities (RV) with the HARPS spectrograph for a sample of 142 giant stars in 17 open clusters. We fit Keplerian orbits when a significant periodic signal is detected. We also study the variation of stellar activity indicators and line-profile variations to discard stellar-induced signals. Results. We present the discovery of a periodic RV signal compatible with the presence of a planet candidate in the 1.15 Gyr open cluster IC 4651 orbiting the 2.06 M⊙ star No. 9122. If confirmed, the planet candidate would have a minimum mass of 7.2 MJ and a period of 747 days. However, we also find that the full width at half maximum (FWHM) of the cross-correlation function (CCF) varies with a period close to the RV, casting doubts on the planetary nature of the signal. We also provide refined parameters for the previously discovered planet around NGC 2423 No. 3, but show evidence that the bisector inverse slope (BIS) of the CCF is correlated with the RV during some of the observing periods. We consider this fact as a warning that this might not be a real planet and that the RV variations could be caused by stellar activity and/or pulsations. Finally, we show that the previously reported signal by a brown dwarf around NGC 4349 No. 127 is presumably produced by stellar activity modulation. Conclusions. The long-term monitoring of several red giants in open clusters has allowed us to find periodic RV variations in several stars. However, we also show that the follow-up of this kind of stars should last more than one orbital period to detect long-term signals of stellar origin. This work highlights the fact that although it is possible to detect planets around red giants, large-amplitude, long-period RV modulations do exist in such stars that can mimic the presence of an orbiting planetary body. Therefore, we need to better understand how such RV modulations behave as stars evolve along the red giant branch and perform a detailed study of all the possible stellar-induced signals (e.g., spots, pulsations, granulation) to comprehend the origin of RV variations. [ABSTRACT FROM AUTHOR]

Objective. Familial Mediterranean fever (FMF) is an autosomal recessive disease due to a MEFV gene mutation. Since Helicobacter pylori infection has been described to increase the severity and frequency of FMF attacks, we evaluate if overgrowth of small intestinal bacterial (SIBO), associated with a release of bacterial products, can affect the response to colchicine in FMF patients poorly responsive to colchicine. Methods. We revised our Periodic Fever Centre database to detect FMF patients who were poorly responsive to colchicine, without a well-defined cause of drug resistance. They were evaluated for SIBO presence, then treated with decontamination therapy. Results. Among 223 FMF patients, 49 subjects show colchicine resistance, and no other known causes of colchicine unresponsiveness has been found in 25 patients. All 25 patients underwent glucose breath test; 20 (80%) of them were positive, thus affected by SIBO. After a successful decontamination treatment, 11 patients (55%) did not show FMF attacks during the following three months (p<0.01), while 9 of them revealed a significant reduction of the number of attacks compared to three months before (p<0.01). Conclusion. The SIBO eradication improves laboratory and clinical features of FMF patients. Thus, patients with unresponsiveness to colchicine treatment should be investigated for SIBO. [ABSTRACT FROM AUTHOR]

The old and metal-rich open cluster NGC 6253 was observed with the Fibre Large Array Multi Element Spectrograph (FLAMES) multi-object spectrograph during an extensive radial velocity campaign monitoring 317 stars with a median of 15 epochs per object. All the targeted stars are located along the upper main sequence of the cluster between 14.8 < V < 16.5. Fifty nine stars are confirmed cluster members both by radial velocities and proper motions and do not show evidence of variability. We detected 45 variable stars among which 25 belong to NGC 6253. We were able to derive an orbital solution for four cluster members (and for two field stars) yielding minimum masses in between ∼90MJ and 噜60MJ and periods between 3 and 220 d. Simulations demonstrated that this survey was sensitive to objects down to 30 MJ at 10 days orbital periods with a detection efficiency equal to 50 per cent. On the basis of these results we concluded that the observed frequency of binaries down to the hydrogen burning limit and up to 20 d orbital period is around (1.5 ± 1.3) per cent in NGC 6253. The overall observed frequency of binaries around the sample of cluster stars is (13 ± 3) per cent. The median radial velocity precision achieved by the GIRAFFE spectrograph in this magnitude range was around ∼240 ms-1 (∼180 ms-1 for UVES). Based on a limited follow-up analysis of seven stars in our sample with the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph we determined that a precision of 35 m s-1 can be reached in this magnitude range, offering the possibility to further extend the variability analysis into the substellar domain. Prospects are even more favourable once considering the upcoming ESPRESSO spectrograph at VLT. [ABSTRACT FROM AUTHOR]

Aims. In this paper we explore the possibility that the recently detected reflected light signal of 51 Peg b could be caused by a ring system around the planet. Methods. We use a simple model to compare the observed signal with the expected signal from a short-period giant planet with rings. We also use simple dynamical arguments to understand the possible geometry of such a system. Results. We provide evidence that, to a good approximation, the observations are compatible with the signal expected from a ringed planet, assuming that the rings are non-coplanar with the orbital plane. However, based on dynamical arguments, we also show that this configuration is unlikely. In the case of coplanar rings we then demonstrate that the incident flux on the ring surface is about 2% the value received by the planet, a value that renders the ring explanation unlikely. Conclusions. The results suggest that the signal observed cannot in principle be explained by a planet+ring system. We discuss, however, the possibility of using reflected light spectra to detect and characterize the presence of rings around short-period planets. Finally, we show that ring systems could have already been detected by photometric transit campaigns, but their signal could have been easily misinterpreted by the expected light curve of an eclipsing binary. [ABSTRACT FROM AUTHOR]

Context. The detection of reflected light from an exoplanet is a difficult technical challenge at optical wavelengths. Even though this signal is expected to replicate the stellar signal, not only is it several orders of magnitude fainter, but it is also hidden among the stellar noise. Aims. We apply a variant of the cross-correlation technique to HARPS observations of 51 Peg to detect the reflected signal from planet 51 Peg b. Methods. Our method makes use of the cross-correlation function (CCF) of a binary mask with high-resolution spectra to amplify the minute planetary signal that is present in the spectra by a factor proportional to the number of spectral lines when performing the cross correlation. The resulting cross-correlation functions are then normalized by a stellar template to remove the stellar signal. Carefully selected sections of the resulting normalized CCFs are stacked to increase the planetary signal further. The recovered signal allows probing several of the planetary properties, including its real mass and albedo. Results. We detect evidence for the reflected signal from planet 51 Peg b at a significance of 3σnoise. The detection of the signal permits us to infer a real mass of 0:46+0:06 >-0:01 MJup (assuming a stellar mass of 1:04 MSun) for the planet and an orbital inclination of 80+10-19 degrees. The analysis of the data also allows us to infer a tentative value for the (radius-dependent) geometric albedo of the planet. The results suggest that 51Peg b may be an inflated hot Jupiter with a high albedo (e.g., an albedo of 0.5 yields a radius of 1:9 ± 0:3 RJup for a signal amplitude of 6:0 ± 0:4 × 10-5). Conclusions. We confirm that the method we perfected can be used to retrieve an exoplanet's reflected signal, even with current observing facilities. The advent of next generation of instruments (e.g. VLT-ESO/ESPRESSO) and observing facilities (e.g. a new generation of ELT telescopes) will yield new opportunities for this type of technique to probe deeper into exoplanets and their atmospheres. [ABSTRACT FROM AUTHOR]

In this work, we present the solution of the stellar spot problem using the Kelvin–Stokes theorem. Our result is applicable for any given location and dimension of the spots on the stellar surface. We present explicitly the result up to the second degree in the limb-darkening law. This technique can be used to calculate very efficiently mutual photometric effects produced by eclipsing bodies occulting stellar spots and to construct complex spot shapes. [ABSTRACT FROM PUBLISHER]

Context. Planetary studies demand precise and accurate stellar parameters as input for inferring the planetary properties. Different methods often provide different results that could lead to biases in the planetary parameters. Aims. In this work, we present a refinement of the spectral synthesis technique designed to treat fast rotating stars better. This method is used to derive precise stellar parameters, namely effective temperature, surface gravity, metallicity, and rotational velocity. The procedure is tested for FGK stars with low and moderate-to-high rotation rates. Methods. The spectroscopic analysis is based on the spectral synthesis package Spectroscopy Made Easy (SME), which assumes Kurucz model atmospheres in LTE. The line list where the synthesis is conducted is comprised of iron lines, and the atomic data are derived after solar calibration. Results. The comparison of our stellar parameters shows good agreement with literature values, both for slowly and for fast rotating stars. In addition, our results are on the same scale as the parameters derived from the iron ionization and excitation method presented in our previous works. We present new atmospheric parameters for 10 transiting planet hosts as an update to the SWEET-Cat catalog. We also re-analyze their transit light curves to derive new updated planetary properties. [ABSTRACT FROM AUTHOR]

Background The onset of a sprue-like enteropathy in association with olmesartan therapy has been recently reported. Aims To perform a systematic review of the literature and describe three additional cases of olmesartan-associated enteropathy. Methods Electronic and manual bibliographic searches were performed to identify original reports in which subjects who were undertaking olmesartan developed a sprue-like enteropathy. Because of the scarcity of studies with adequate sample size, case series with less than 10 patients and case reports were also considered. Data extraction was performed independently by two reviewers. Results A total of 11 publications met our pre-defined inclusion criteria, for an overall number of 54 patients (including our series). Almost all patients presented with diarrhoea and weight loss. Normocytic normochromic anaemia and hypoalbuminaemia were the commonest laboratory defects at presentation. Antibody testing for coeliac disease was always negative. Variable degrees of duodenal villous atrophy were present in 98% of patients, while increased intra-epithelial lymphocytes were documented in only 65% of cases. After discontinuation of olmesartan, all reported patients achieved resolution of signs and symptoms. Conclusions Although the available evidence is limited, the olmesartan-associated sprue-like enteropathy may be considered as a distinct clinical entity, and should be included in the differential diagnosis when serological testing for coeliac disease is negative. [ABSTRACT FROM AUTHOR]

We present high-precision radial-velocity measurements of three solar-type stars: HD13908, HD159243, and HIP 91258. The observations were made with the SOPHIE spectrograph at the 1.93 m telescope of the Observatoire de Haute-Provence (France). They show that these three bright stars host exoplanetary systems composed of at least two companions. HD13908 b is a planet with a minimum mass of 0.865 ± 0.035 MJup on a circular orbit with a period of 19.382 ± 0.006 days. There is an outer massive companion in the system with a period of 931 ± 17 days, e = 0.12 ± 0.02, and a minimum mass of 5.13 ± 0.25 MJup. The star HD159243 also has two detected companions with respective masses, periods, and eccentricities of Mp= 1.13 ± 0.05 and 1.9 ± 0.13 MJup, P = 12.620 ± 0.004 and 248.4 ± 4.9 days, and e = 0.02 ± 0.02 and 0.075 ± 0.05. Finally, the star HIP 91258 has a planetary companion with a minimum mass of 1.068 ± 0.038 MJup, an orbital period of 5.0505 ± 0.0015 days, and a quadratic trend indicating an outer planetary or stellar companion that is as yet uncharacterized. The planet-hosting stars HD13908, HD159243, and HIP 91258 are main-sequence stars of spectral types F8V, G0V, and G5V, respectively, with moderate activity levels. HIP 91258 is slightly over-metallic, while the other two stars have solar-like metallicity. The three systems are discussed in the frame of formation and dynamical evolution models of systems composed of several giant planets. [ABSTRACT FROM AUTHOR]

Context. Precise stellar parameters are crucial in exoplanet research for correctly determining the planetary parameters. For stars hosting a transiting planet, determining the planetary mass and radius depends on the stellar mass and radius, which in turn depend on the atmospheric stellar parameters. Different methods can provide different results, which leads to different planet characteristics. Aims. In this paper, we use a uniform method to spectroscopically derive stellar atmospheric parameters, chemical abundances, stellar masses, and stellar radii for a sample of 90 transit hosts. Surface gravities are also derived photometrically using the stellar density as derived from the light curve. We study the effect of using these different surface gravities on the determination of the chemical abundances and the stellar mass and radius. Methods. A spectroscopic analysis based on Kurucz models in local thermodynamical equilibrium was performed through theMOOG code to derive the atmospheric parameters and the chemical abundances. The photometric surface gravity was determined through isochrone fitting and the use of the stellar density, directly determined from the light curve. Stellar masses and radii are determined through calibration formulae. Results. Spectroscopic and photometric surface gravities differ, but this has very little effect on the precise determination of the stellar mass in our spectroscopic analysis. The stellar radius, and hence the planetary radius, is most affected by the surface gravity discrepancies. For the chemical abundances, the difference is, as expected, only noticeable for the abundances derived from analyzing lines of ionized species. [ABSTRACT FROM AUTHOR]

Stellar-activity features such as spots can complicate the determination of planetary parameters through spectroscopic and photometric observations. The overlap of a transiting planet and a stellar spot, for instance, can produce anomalies in the transit light-curves that may lead to an inaccurate estimation of the transit duration, depth, and timing. These inaccuracies can for instance affect the precise derivation of the planet radius. We present the results of a quantitative study on the effects of stellar spots on high-precision transit light-curves. We show that spot anomalies can lead to an estimate of a planet radius that is 4% smaller than the real value. Likewise, the transit duration may be estimated about 4%, longer or shorter. Depending on the size and distribution of spots, anomalies can also produce transit-timing variations (TTVs) with significant amplitudes. For instance, TTVs with signal amplitudes of 200 s can be produced when the spot is completely dark and has the size of the largest Sun spot. Our study also indicates that the smallest size of a stellar spot that still has detectable effects on a high-precision transit light-curve is around 0.03 time the stellar radius for typical Kepler Telescope precision. We also show that the strategy of including more free parameters (such as transit depth and duration) in the fitting procedure to measure the transit time of each individual transit will not produce accurate results for active stars. [ABSTRACT FROM AUTHOR]

The Rossiter-McLaughlin (hereafter RM) effect is a key tool for measuring the projected spin-orbit angle between stellar spin axes and orbits of transiting planets. However, the measured radial velocity (RV) anomalies produced by this effect are not intrinsic and depend on both instrumental resolution and data reduction routines. Using inappropriate formulas to model the RM eβect introduces biases, at least in the projected velocity V sin i⋆ compared to the spectroscopic value. Currently, only the iodine cell technique has been modeled, which corresponds to observations done by, e.g., the HIRES spectrograph of the Keck telescope. In this paper, we provide a simple expression of the RM effect specially designed to model observations done by the Gaussian fit of a cross-correlation function (CCF) as in the routines performed by the HARPS team. We derived a new analytical formulation of the RV anomaly associated to the iodine cell technique. For both formulas, we modeled the subplanet mean velocity vpand dispersion βp accurately taking the rotational broadening on the subplanet profile into account. We compare our formulas adapted to the CCF technique with simulated data generated with the numerical software SOAP-T and find good agreement up to V sin i⋆ ≲β 20 km s−1. In contrast, the analytical models simulating the two diβerent observation techniques can disagree by about 10β in V sin i⋆ for large spin-orbit misalignments. It is thus important to apply the adapted model when fitting data. [ABSTRACT FROM AUTHOR]

We present an improved version of SOAP named "SOAP-T", which can generate the radial velocity variations and light curves for systems consisting of a rotating spotted star with a transiting planet. This tool can be used to study the anomalies inside transit light curves and the Rossiter-McLaughlin effect, to better constrain the orbital configuration and properties of planetary systems and the active zones of their host stars. Tests of the code are presented to illustrate its performance and to validate its capability when compared with analytical models and real data. Finally, we apply SOAP-T to the active star, HAT-P-11, observed by the NASA Kepler space telescope and use this system to discuss the capability of this tool in analyzing light curves for the cases where the transiting planet overlaps with the star's spots. [ABSTRACT FROM AUTHOR]

ABSTRACT In this work, we investigate the problem concerning the presence of additional bodies gravitationally bound with the WASP-3 system. We present eight new transits of this planet gathered between 2009 May and 2011 September by using the 30-cm telescope at the Crow Observatory-Portalegre, and analyse all the photometric and radial velocity data published so far. We did not observe significant periodicities in the Fourier spectrum of the observed minus calculated (O − C) transit timing and radial velocity diagrams (the highest peak having false-alarm probabilities of 56 and 31 per cent, respectively) or long-term trends. Combining all the available information, we conclude that the radial velocity and transit timing techniques exclude, at 99 per cent confidence limit, any perturber more massive than M ≳ 100 Mearth with periods up to 10 times the period of the inner planet. We also investigate the possible presence of an exomoon in this system and determine that considering the scatter of the O − C transit timing residuals a coplanar exomoon would likely produce detectable transits. This hypothesis is however apparently ruled out by observations conducted by other researchers. In the case where the orbit of the moon is not coplanar, the accuracy of our transit timing and transit duration measurements prevents any significant statement. Interestingly, on the basis of our reanalysis of SOPHIE data we noted that WASP-3 passed from a less active ( [ABSTRACT FROM AUTHOR]

Most of the exoplanet science is dependent on the stellar knowledge. One of them that has to be understood is the magnetic activity when we search for planets with radial velocity or photometry measurements. The main shape of stellar activity and spots properties have to be understood, for example, to choose the best targets to search for low-mass planets in the habitable zone or to derive the accurate parameters of a planetary system. With that aim, we show in this presentation how these studies lead to give clues on spots latitudes and on the long term variation of stellar activity. The properties of magnetic activity on the low rotators solar-type stars are not easily reachable by other techniques (spectropolarimetry or Doppler imaging) and these studies should be used to constrain theories of stellar dynamo. [ABSTRACT FROM PUBLISHER]

The photometric and RV techniques, although extremely efficient to detect and characterize planets, are, however, indirect techniques (as well as astrometry). Phenomena such as stellar pulsation, inhomogeneous convection, spots or magnetic cycles can prevent us from finding planets or they might degrade the parameters estimation. We will consider the challenges related to the knowledge of stellar activity for the next decade: detect telluric planets in the habitable zone of their stars (from G to M dwarfs), understand the activity in the low-mass end of M dwarf (on which will focus future near-infrared high-resolution spectrograph like SPIRou or CARMENES), limitation to the process of summing several transit observations (in order to characterize the atmospheric components) due to the variability of stellar activity (from the ground or with Spitzer or JWST), as well as the methods proposed and used to overcome this issue. [ABSTRACT FROM PUBLISHER]

ABSTRACT We report on VLT/UVES high-resolution spectra of four members of the old metal-rich open cluster NGC 6253: a main-sequence star, two red-clump stars and a blue straggler. We performed equivalent width analysis and derived Fe, Si, Ca, Ti, Cr and Ni abundances as well as abundance ratios. For our main-sequence star, we obtained a metallicity of (rms), whereas for the two giants we found that our metallicities are on average +0.19 ± 0.13 (rms), lower than what was determined for the same stars in previous studies. We also found that, within the uncertainties, the abundance ratios of α and iron-peak elements match those in the solar surroundings, with the possible exception of Si in two giant stars in our sample. [ABSTRACT FROM AUTHOR]

Context. The recent results of the HARPS and Kepler surveys provided us with a bounty of extrasolar systems. While the two teams extensively analyzed each of their data-sets, little work has been done comparing the two. Aims. We study a subset of the planetary population whose characterization is simultaneously within reach of both instruments. We compare the statistical properties of planets in systems with m sin i > 5-10 M☉ and R > 2 R☉, as inferred from the HARPS and Kepler surveys, respectively. If we assume that the underlying population has the same characteristics, the different detection sensitivity to the orbital inclination relative to the line of sight allows us to probe the planets' mutual inclination. Methods. We considered the frequency of systems with one, two, and three planets as dictated by HARPS data. We used Kepler's planetary period and host mass and radius distributions (corrected from detection bias) to model planetary systems in a simple, yet physically plausible way. We then varied the mutual inclination between planets in a system according to different prescriptions (completely aligned, Rayleigh distributions, and isotropic) and compared the transit frequencies with one, two, or three planets with those measured by Kepler. Results. The results show that the two datasets are compatible, a remarkable result especially because there are no tunable knobs other than the assumed inclination distribution. For msin i cutoffs of 7-10 M☉, which are those expected to correspond to the radius cutoff of 2 R☉, we conclude that the results are better described by a Rayleigh distribution with a mode of 1° or smaller.We show that the best-fit scenario only becomes a Rayleigh distribution with a mode of 5° if we assume a quite extreme mass-radius relationship for the planetary population. Conclusions. These results have important consequences for our understanding of the role of several proposed formation and evolution mechanisms. They confirm that planets are likely to have been formed in a disk and show that most planetary systems evolve quietly without strong angular momentum exchanges such as those produced by Kozai mechanism or planet scattering. [ABSTRACT FROM AUTHOR]

ABSTRACT The transit timing variation (TTV) method allows the detection of non-transiting planets through their gravitational perturbations. Since TTVs are strongly enhanced in systems close to mean-motion resonances (MMRs), even a low-mass planet can produce an observable signal. This technique has thus been proposed to detect terrestrial planets. In this Letter, we analyse TTV signals for systems in or close to MMR in order to illustrate the difficulties arising in the determination of planetary parameters. TTVs are computed numerically with an N-body integrator for a variety of systems close to MMR. The main features of these TTVs are also derived analytically. Systems deeply inside of the MMR do not produce particularly strong TTVs, while those close to MMR generate quasi-periodic TTVs characterized by a dominant long-period term and a low-amplitude remainder. If the remainder is too weak to be detected, then the signal is strongly degenerate and this prevents the determination of the planetary parameters. Even though an Earth-mass planet can be detected by the TTV method if it is close to an MMR, it may not be possible to assert that this planet is actually an Earth-mass planet. On the other hand, if the system is right in the centre of an MMR, the high-amplitude oscillation of the TTV signal vanishes and the detection of the perturber becomes as difficult as it is far from the MMR. [ABSTRACT FROM AUTHOR]

We present a study of the stellar parameters and iron abundances of 18 giant stars in six open clusters. The analysis was based on high-resolution and high-S/N spectra obtained with the UVES spectrograph (VLT-UT2). The results complement our previous study where 13 clusters were already analyzed. The total sample of 18 clusters is part of a program to search for planets around giant stars. The results show that the 18 clusters cover a metallicity range between -0.23 and +0.23 dex. Together with the derivation of the stellar masses, these metallicities will allow the metallicity and mass effects to be disentangled when analyzing the frequency of planets as a function of these stellar parameters. [ABSTRACT FROM AUTHOR]

Aliment Pharmacol Ther 2010; 32: 209–214 Background Non-steroidal anti-inflammatory drugs (NSAIDs) can cause serious gastrointestinal side effects. Faecal calprotectin assay represents a simple and practical method for diagnosis of NSAID enteropathy. Intestinal micro-organisms are necessary for the development of NSAID-induced small bowel lesions and hence it has been suggested that probiotics could protect against NSAID enteropathy. Aim To evaluate the effect of a probiotic mixture in comparison with placebo on faecal calprotectin concentrations (FCCs) in healthy volunteers receiving indomethacin. Methods In a double-blind, cross-over trial, 20 healthy volunteers ingested a daily dose of probiotic mixture ( VSL#3) or placebo for 21 days. From day 16 to day 19, all subjects were also administered 50 mg/day of indomethacin. FCCs were measured the day before starting probiotic/placebo ingestion (T0), and every day from day 15 to day 21. Results During dosing with probiotic, median FCCs were significantly increased only at day 17 with respect to T0 values, whereas during dosing with placebo, they were significantly increased at every day from day 17 to day 21 with respect to T0 values. Conclusions Treatment with VSL#3 before and during indomethacin therapy significantly reduces FCCs in healthy subjects with respect to placebo, suggesting that this approach could be useful in decreasing indomethacin-induced intestinal inflammation. [ABSTRACT FROM AUTHOR]

The radiopharmaceutical [153Sm]Sm-EDTMP is administered for painful bone metastases with the standard dosage of 37 MBq/kg, without evaluation of patient individual characteristics. For a better dose estimate in vivo stability should be considered, because labelled and unlabelled samarium do not have the same metabolic pathway. We evaluated radiopharmaceutical in vitro stability, measuring the activity by beta and gamma spectrometry. Subsequently we verified in vivo stability on serial blood and urine samples. The percentage of the unlabelled radiopharmaceutical is high and, on the basis of radiochemical data as well as blood clearance and urine excretion, we calculated the main parameters for a preliminary biokinetic model. [ABSTRACT FROM AUTHOR]

Background Breath tests represent a valid and non-invasive diagnostic tool in many gastroenterological conditions. The rationale of hydrogen-breath tests is based on the concept that part of the gas produced by colonic bacterial fermentation diffuses into the blood and is excreted by breath, where it can be quantified easily. There are many differences in the methodology, and the tests are increasingly popular. Aim The Rome Consensus Conference was convened to offer recommendations for clinical practice about the indications and methods of H2-breath testing in gastrointestinal diseases. Methods Experts were selected on the basis of a proven knowledge⁄expertise in H2-breath testing and divided into Working Groups (methodology; sugar malabsorption; small intestine bacterial overgrowth; oro-coecal transit time and other gas-related syndromes). They performed a systematic review of the literature, and then formulated statements on the basis of the scientific evidence, which were debated and voted by a multidisciplinary Jury. Recommendations were then modified on the basis of the decisions of the Jury by the members of the Expert Group. Results and conclusions The final statements, graded according to the level of evidence and strength of recommendation, are presented in this document; they identify the indications for the use of H2-breath testing in the clinical practice and methods to be used for performing the tests. [ABSTRACT FROM AUTHOR]

Background Despite the reported tolerance to a low dose of lactose, many lactose malabsorbers follow a rigorous lactose-free diet also avoiding lactose-containing drugs. Up to now, only a few case reports have described the onset of gastrointestinal symptoms in lactose malabsorbers following the ingestion of these drugs. It has been suggested that capsules/tablets contain no more than 400 mg of lactose. Aim To evaluate breath H2 excretion and intolerance symptoms after ingestion of a capsule containing 400 mg of lactose or placebo through a randomized, cross-over, double-blind, controlled study. Methods Seventy-seven lactose maldigesters with intolerance underwent two H2 breath tests with both 400 mg of lactose and 400 mg of placebo. Gastrointestinal symptoms occurring in the 8 h following the ingestion of different substrates were evaluated by a visual-analogue scale. Results Ingestion of 400 mg of lactose did not cause a significant difference in breath H2 excretion or in the severity of gastrointestinal symptoms compared to placebo. Conclusion In patients with lactase deficiency, drugs containing 400 mg of lactose or less can be used safely. [ABSTRACT FROM AUTHOR]

Many biological samples (urines and faeces) have been analyzed by means of chromatographic extraction columns, utilizing two different resins (AG 1-X2 resin chloride and TRU), in order to detect the possible internal contamination of 239+240Pu and 241Am for some workers of a reprocessing nuclear plant in the decommissioning phase. The results obtained show on one hand the great suitability of the first resin for the determination of plutonium, and on the other, the great selectivity of the second one for the determination of americium. [ABSTRACT FROM AUTHOR]

During the radiation protection surveillance of exposed workers samples of urine and faeces were collected. Anion exchange chromatography was used for the separation of Pu. We investigated a technique to purify and separate Pu and Am isotopes using extraction chromatography with TRU resin. We tested different procedures to dissolve organic matter and eliminate interferences for chromatographic elution. At the end of the process we have succeeded in electroplating the two radionuclides separately. We have also studied extraction chromatography with UTEVA resin to purify Pu isotopes and separate it from natural uranium radioisotopes, present in some biological samples. We validated a method for the determination of Pu in biological samples and a rather constant chemical yield and resolved peaks were obtained. The preliminary studies on TRU resin have indicated that it is possible to combine extraction and anion-exchange chromatography for analysing separately Pu and Am isotopes from the same sample aliquote. [ABSTRACT FROM AUTHOR]

OBJECTIVE:: To evaluate the efficacy of the addition to milk, 5?min and 10?h before its consumption, of a lactase obtained from Kluyveromyces lactis in lactose malabsorbers with intolerance. DESIGN:: Double-blind, placebo-controlled, crossover study. SETTING:: University Hospital. SUBJECTS:: In total, 11 male and 19 female (aged from 18 to 65?y, mean age 43.3?y) lactose malabsorbers with intolerance participated. INTERVENTIONS:: Each patient underwent three H2 breath tests, in a random order. We used 400?ml of cow's semiskimmed milk as substrate and aß-galactosidase obtained from K. lactis. The test A was carried out adding to the milk the enzyme (3000?UI), 10?h before its consumption; the test B was performed adding theß-galactosidase (6000?UI) 5?min before milk ingestion and the test C was made using placebo. We evaluated the maximum breath H2 concentration, the cumulative H2 excretion and a clinical score based on intolerance symptoms (bloating, abdominal pain, flatulence and diarrhoea). RESULTS:: Our study showed a significant reduction of the mean maximum H2 concentration after both test A (12.07±7.8?p.p.m.) and test B (13.97±7.99?p.p.m.) compared with test C (51.46±16.12?p.p.m.) (ANOVA F=54.33, P<0.001). Similarly, there was a significant reduction of the mean cumulative H2 excretion after both test A (1428±1156?p.p.m.) and test B (1761±966?p.p.m.) compared with test C (5795±2707?p.p.m.) (ANOVA F=31.46, P<0.001). We also observed a significant reduction of the mean clinical score after both test A (0.36±0.55) and test B (0.96±0.85) compared with test C (3.7±0.79) (ANOVA F=106.81, P<0.001). Moreover, with regard to the mean clinical score, there was a significant reduction after test A with respect to test B (Bonferroni's P=0.03). CONCLUSIONS:: Our study shows that in lactose malabsorbers with intolerance, the lactase obtained from K. lactis can represent a valid therapeutic strategy, with objective and subjective efficacy and without side effects.European Journal of Clinical Nutrition (2005) 59, 489-493. doi:10.1038/sj.ejcn.1602098 Published online 26 January 2005 [ABSTRACT FROM AUTHOR]

Within the radiation protection physical surveillance program of some workers, involved in the decommissioning operations of a nuclear reprocessing plant of the Italian National Agency for New Technologies Energy and Environment, CR Salluggia (ENEA) in the North of Italy, some radiotoxicological analyses, on human urines, have been carried out, in order to determine the possible internal contamination of 241Am. After an in-depth study of a former extraction chromatographic method, based on the use of Microthene-722 supporting HDEHP, a more suitable method has been developed and adopted in our laboratory, based on the use of TRU-Resin. This paper reports the results obtained with these two procedures as well as a comparison between them. [ABSTRACT FROM AUTHOR]

Background/Aims: Lactobacilli are used in the prevention and treatment of several diseases, but they are also known to play a role in the pathogenesis of dental caries. The aim of our study was to evaluate whether the oral administration of lactobacilli could change the salivary counts of these bacteria compared with placebo. Moreover, lactobacilli were administered in liquid and in capsule form to determine the role of direct contact with the oral cavity. Methods: Thirty-five healthy volunteers were randomized into three groups to receive lactobacilli and/or placebo for 45 days: group A (n = 14) received probiotics in capsules and placebo in liquid form; group B (n = 16) took liquid probiotics and placebo in capsules, and group C (n = 5) used placebo in both liquid and capsule form. Streptococcus mutans populations served as control. The salivary counts of lactobacilli and S. mutans were measured semi-quantitatively using the CRT[sup ®] bacteria kit. Results: Compared with placebo, the oral administration of probiotics, both in capsules and in liquid form, significantly increases salivary counts of lactobacilli (p = 0.005 and p = 0.02, respectively). S. mutans populations were not significantly modified. Conclusions: The increased salivary counts of lactobacilli may indicate the need to closely monitor the dental health of patients undergoing long-term probiotics treatment, even when this treatment is administrated in a form that avoids direct contact with the oral cavity. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]