Search

Context. The ESA PLAnetary Transits and Oscillations of stars (PLATO) mission will search for terrestrial planets in the habitable zone of solar-type stars. Because of telemetry limitations, PLATO targets need to be pre-selected. Aims. In this paper, we present an all sky catalogue that will be fundamental to selecting the best PLATO fields and the most promising target stars, deriving their basic parameters, analysing the instrumental performances, and then planing and optimising follow-up observations. This catalogue also represents a valuable resource for the general definition of stellar samples optimised for the search of transiting planets. Methods. We used Gaia Data Release 2 (DR2) astrometry and photometry and 3D maps of the local interstellar medium to isolate FGK (V$\leq$13) and M (V$\leq$16) dwarfs and subgiant stars. Results. We present the first public release of the all-sky PLATO Input Catalogue (asPIC1.1) containing a total of 2 675 539 stars including 2 378 177 FGK dwarfs and subgiants and 297 362 M dwarfs. The median distance in our sample is 428 pc for FGK stars and 146 pc for M dwarfs, respectively. We derived the reddening of our targets and developed an algorithm to estimate stellar fundamental parameters (Teff, radius, mass) from astrometric and photometric measurements. Conclusions. We show that the overall (internal+external) uncertainties on the stellar parameter determined in the present study are $\sim$230 K (4%) for the effective temperatures, $\sim$0.1 R$_{\odot}$ (9%) for the stellar radii, and $\sim$0.1 M$_{\odot}$ (11%) for the stellar mass. We release a special target list containing all known planet hosts cross-matched with our catalogue., Accepted for publication in Astronomy & Astrophysics

Context. Young stars and multi-planet systems are two types of primary objects that allow us to study, understand, and constrain planetary formation and evolution theories. Aims. We validate the physical nature of two Neptune-sized planets transiting TOI-942 (TYC 5909-319-1), a previously unacknowledged young star (50−20+30 Myr) observed by the TESS space mission in Sector 5. Methods. Thanks to a comprehensive stellar characterization, TESS light curve modeling and precise radial-velocity measurements, we validated the planetary nature of the TESS candidate and detected an additional transiting planet in the system on a larger orbit. Results. From photometric and spectroscopic observations we performed an exhaustive stellar characterization and derived the main stellar parameters. TOI-942 is a relatively active K2.5V star (log R′HK = −4.17 ± 0.01) with rotation period Prot = 3.39 ± 0.01 days, a projected rotation velocity v sin i⋆ = 13.8 ± 0.5 km s−1, and a radius of ~0.9 R⊙. We found that the inner planet, TOI-942 b, has an orbital period Pb = 4.3263 ± 0.0011 days, a radius Rb = 4.242−0.313+0.376 R⊕, and a mass upper limit of 16 M⊕ at 1σ confidence level. The outer planet, TOI-942 c, has an orbital period Pc = 10.1605−0.0053+0.0056 days, a radius Rc = 4.793−0.351+0.410 R⊕, and a mass upper limit of 37 M⊕ at 1σ confidence level.

In this work, we present the analysis of 976 814 FGKM dwarf and sub-giant stars in the TESS Full Frame Images (FFIs) of the Southern ecliptic hemisphere. We present a new pipeline, DIAmante, developed to extract optimized, multi-sector 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$\rm_{\oplus}$ and 2.6 R$\rm_J$ with median value of 1 R$\rm_J$ and the period distribution ranges between 0.25 days and 105 days with median value of 3.8 days. The sample contains four long period candidates (P>50 days) one of which is new and 64 candidates with periods between 10 and 50 days (42 new ones). In the small planet radius domain (R, Accepted by MNRAS. Data available at https://archive.stsci.edu/hlsp/diamante

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, minimising 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 them are strong candidate exoplanets. Because of the limited S/N, we did not find any Earth or super-Earth. We identified two Neptune-size planets orbiting stars with $R_{\star}, Comment: 19 pages, 12 figures, 3 tables. Accepted for publication in MNRAS on May 20, 2020. PATHOS light curves are available at MAST as HLSP at https://archive.stsci.edu/hlsp/pathos

Six decades and counting, the formation of hot ~20,000-30,000 K Extreme Horizontal Branch (EHB) stars in Galactic Globular Clusters remains one of the most elusive quests in stellar evolutionary theory. Here we report on two discoveries shattering their currently alleged stable luminosity. The first EHB variability is periodic and cannot be ascribed to binary evolution nor pulsation. Instead, we here attribute it to the presence of magnetic spots: superficial chemical inhomogeneities whose projected rotation induces the variability. The second EHB variability is aperiodic and manifests itself on time-scales of years. In two cases, the six-year light curves display superflare events a mammoth several million times more energetic than solar analogs. We advocate a scenario where the two spectacular EHB variability phenomena are different manifestations of diffuse, dynamo-generated, weak magnetic fields. Ubiquitous magnetic fields, therefore, force an admittance into the intricate matrix governing the formation of all EHBs, and traverse to their Galactic field counterparts. The bigger picture is one where our conclusions bridge similar variability/magnetism phenomena in all radiative-enveloped stars: young main-sequence stars, old EHBs and defunct white dwarfs., Author's version of the main article (23 pages) and Supplementary Information (22 pages) combined into a single pdf (45 pages). Readers invited to read the Nature Astronomy Published version available at this url: https://www.nature.com/articles/s41550-020-1113-4

We employed recent Gaia/DR2 data to investigate the dynamical status of the nearby (300 pc), old (2.5 Gyr) open cluster Ruprecht~147. We found prominent leading and trailing tails of stars along the cluster orbit, which demonstrates that Ruprecht~147 is losing stars at fast pace. Star counts indicate the cluster has a core radius of 33.3 arcmin, and a tidal radius of 137.5 arcmin. The cluster also possesses an extended corona, which cannot be reproduced by a simple King model. We computed the present-day cluster mass using its luminosity and mass function, and derived an estimate of 234$\pm$52 $M_{\odot}$. We also estimated the cluster original mass using available recipes extracted from N-body simulations obtaining a mass at birth of 50000$\pm$6500 $M_{\odot}$. Therefore dynamical mass loss, mostly caused by tidal interaction with the Milky Way, reduced the cluster mass by about 99\%. We then conclude that Ruprecht~147 is rapidly dissolving into the general Galactic disc., 13 pages, 10 figure, in press in the Astronomical Journal

The number of exoplanet detections continues to grow following the development of better instruments and missions. Key steps for the understanding of these worlds comes from their characterization and its statistical studies. We explore the metallicity-period-mass diagram for known exoplanets by using an updated version of The Stellar parameters for stars With ExoplanETs CATalog (SWEET-Cat), a unique compilation of precise stellar parameters for planet-host stars provided for the exoplanet community. Here we focus on the planets with minimum mass below 30 M$_{\oplus}$ which seems to present a possible correlation in the metallicity-period-mass diagram where the mass of the planet increases with both metallicity and period. Our analysis suggests that the general observed correlation may be not fully explained by observational biases. Additional precise data will be fundamental to confirm or deny this possible correlation., Comment: 12 pages, 9 Figures, Accepted for MNRAS

The TESS mission will survey ~85 % 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 characterise 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 minimise 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 16641 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 ~1 % on the 6.5-hour timescale; 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., 19 pages, 15 figures (3 at low resolution), 3 tables. Accepted for publication in MNRAS on October 4, 2019. PATHOS data products are available at MAST as HLSP at http://archive.stsci.edu/hlsp/pathos/

[Abridged] Context. Stellar activity is an important source of systematic errors and uncertainties in the characterization of exoplanets. Most of the techniques used to correct for this activity focus on an ad hoc data reduction. Aims. We have developed a software for the combined fit of transits and stellar activity features in high-precision long-duration photometry. Our aim is to take advantage of the modelling to derive correct stellar and planetary parameters, even in the case of strong stellar activity. Methods. We use an analytic approach to model the light curve. The code KSint, modified by adding the evolution of active regions, is implemented into our Bayesian modelling package PASTIS. The code is then applied to the light curve of CoRoT-2. The light curve is divided in segments to reduce the number of free parameters needed by the fit. We perform a Markov chain Monte Carlo analysis in two ways. In the first, we perform a global and independent modelling of each segment of the light curve, transits are not normalized and are fitted together with the activity features, and occulted features are taken into account during the transit fit. In the second, we normalize the transits with a model of the non-occulted activity features, and then we apply a standard transit fit, which does not take the occulted features into account. Results. Our model recovers the activity features coverage of the stellar surface and different rotation periods for different features. We find variations in the transit parameters of different segments and show that they are likely due to the division applied to the light curve. Neglecting stellar activity or even only bright spots while normalizing the transits yields a $\sim 1.2\sigma$ larger and $2.3\sigma$ smaller transit depth, respectively. The stellar density also presents up to $2.5\sigma$ differences depending on the normalization technique..., Comment: 14 pages, 7 figures, 6 tables, accepted on A&A. arXiv admin note: text overlap with arXiv:1604.03979

With about 2000 extrasolar planets confirmed, the results show that planetary systems have a whole range of unexpected properties. We present a full investigation of the HD219828 system, a bright metal-rich star for which a hot neptune has previously been detected. We used a set of HARPS, SOPHIE, and ELODIE radial velocities to search for the existence of orbiting companions to HD219828. A dynamical analysis is also performed to study the stability of the system and to constrain the orbital parameters and planet masses. We announce the discovery of a long period (P=13.1years) massive (msini=15.1MJup) companion (HD219828c) in a very eccentric orbit (e=0.81). The same data confirms the existence of a hot-neptune, HD219828b, with a minimum mass of 21 MEarth and a period of 3.83days. The dynamical analysis shows that the system is stable. The HD219828 system is extreme and unique in several aspects. First, among all known exoplanet systems it presents an unusually high mass ratio. We also show that systems like HD219828, with a hot neptune and a long-period massive companion are more frequent than similar systems with a hot jupiter instead. This suggests that the formation of hot neptunes follows a different path than the formation of their hot jovian counterparts. The high mass, long period, and eccentricity of HD219828c also make it a good target for Gaia astrometry as well as a potential target for atmospheric characterisation, using direct imaging or high-resolution spectroscopy. Astrometric observations will allow us to derive its real mass and orbital configuration. If a transit of HD219828b is detected, we will be able to fully characterise the system, including the relative orbital inclinations. With a clearly known mass, HD219828c may become a benchmark object for the range in between giant planets and brown dwarfs., Comment: Astronomy & Astrophysics, in press

The old and metal rich open cluster NGC 6253 was observed with the 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 $, Comment: Accepted by MNRAS

We report on novel observations of HAT-P-1 aimed at constraining the optical transmission spectrum of the atmosphere of its transiting Hot-Jupiter exoplanet. Ground-based differential spectrophotometry was performed over two transit windows using the DOLORES spectrograph at the Telescopio Nazionale Galileo (TNG). Our measurements imply an average planet to star radius ratio equal to $\rm R_p/R_{\star}$=(0.1159$\pm$0.0005). This result is consistent with the value obtained from recent near infrared measurements of this object but differs from previously reported optical measurements being lower by around 4.4 exoplanet scale heights. Analyzing the data over 5 different spectral bins 600\AA$\,$ wide we observed a single peaked spectrum (3.7 $\rm\sigma$ level) with a blue cut-off corresponding to the blue edge of the broad absorption wing of sodium and an increased absorption in the region in between 6180-7400\AA. We also infer that the width of the broad absorption wings due to alkali metals is likely narrower than the one implied by solar abundance clear atmospheric models. We interpret the result as evidence that HAT-P-1b has a partially clear atmosphere at optical wavelengths with a more modest contribution from an optical absorber than previously reported., Comment: Accepted by ApJ

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. 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. Our method makes use of the cross-correlation function 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. We detect evidence for the reflected signal from planet 51 Peg b at a significance of 3\sigma_noise. The detection of the signal permits us to infer a real mass of 0.46^+0.06_-0.01 M_Jup (assuming a stellar mass of 1.04\;M_Sun) 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 \pm 0.3 R_Jup for a signal amplitude of 6.0\pm0.4 x 10^-5). 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 observing facilities will yield new opportunities for this type of technique to probe deeper into exoplanets., Comment: 9 pages, 6 figures

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.

Transmission spectroscopy during planetary transits, which is based on the measurements of the variations of planet-to-star radius ratio as a function of wavelength, is a powerful technique to study the atmospheric properties of transiting planets. One of the main limitation of this technique is the effects of stellar activity, which up until now, have been taken into account only by assessing the effect of non-occulted stellar spots on the estimates of planet-to-star radius ratio. In this paper, we study, for the first time, the impact of the occultation of a stellar spot and plage on the transmission spectra of transiting exoplanets. We simulated this effect by generating a large number of transit light curves for different transiting planets, stellar spectral types, and for different wavelengths. Results of our simulations indicate that the anomalies inside the transit light curve can lead to a significant underestimation or overestimation of the planet-to-star radius ratio as a function of wavelength. At short wavelengths, the effect can reach to a difference of up to 10% in the planet-to-star radius ratio, mimicking the signature of light scattering in the planetary atmosphere. Atmospheric scattering has been proposed to interpret the increasing slopes of transmission spectra toward blue for exoplanets HD 189733b and GJ 3470b. Here we show that these signatures can be alternatively interpreted by the occultation of stellar plages. Results also suggest that the best strategy to identify and quantify the effects of stellar activities on the transmission spectrum of a planet is to perform several observations during the transit epoch at the same wavelength. This will allow for identifying the possible variations in transit depth as a function of time due to stellar activity variability., 7 pages, 6 figures, Accepted for publication in A&A

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 explicitely 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., Resubmitted to MNRAS after accounting for minor comments of second review, 9 pages, 5 figures, software available at http://eduscisoft.com/KSINT/

Context. Precise stellar parameters are crucial in exoplanet research for correctly determining of the planetary parameters. For stars hosting a transiting planet, determining of 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.}%Spectroscopic surface gravities have shown to be poorly constrained, but the photometry of the transiting planet can provide an independent measurement of the surface gravity. 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 LTE was performed through the MOOG 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 noticable for the abundances derived from analyzing of lines of ionized species., 12 pages, 6 figures, 5 tables, accepted to A&A

Stellar activity features such as spots can create complications in determining 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 inaccurate estimation of the transit duration, depth and timing. For instance such inaccuracies can affect the precise derivation of the planet's radius. In this paper, 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 the estimate of a planet radius that is 4% smaller than the real value. The effects on the transit duration can also be of the order of 4%, longer or shorter. Depending on the size and distribution of spots, anomalies can also produce transit timing variations with significant amplitudes. For instance, TTVs with signal amplitudes of 200 seconds can be produced when the spot is completely dark and as large as the largest Sun spot. Our study also indicates that the minimum size of a stellar spot with detectable affects on the 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 in the case of active stars., Comment: 7 pages, 9 figures, accepted for publication in Astronomy & Astrophysics

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 effect introduces biases, at least in the projected velocity Vsin(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 also a new analytical formulation of the RV anomaly associated to the iodine cell technique. For both formulas, we modeled the subplanet mean velocity v_p and dispersion beta_p 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 Vsin(i) < 20 km/s. In contrast, the analytical models simulating the two different observation techniques can disagree by about 10 sigma in Vsin(i) for large spin-orbit misalignments. It is thus important to apply the adapted model when fitting data., 16 pages, 11, figures, accepted in Astronomy and Astrophysics. Public code available at http://www.astro.up.pt/resources/arome

We present an improved version of SOAP (Boisse et al. 2012) 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 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., Comment: 9 pages, 7 figures, accepted for publication in Astronomy and Astrophysics

In this work we investigate the problem concerning the presence of additional bodies gravitationally bounded with the WASP-3 system. We present eight new transits of this planet 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 per cent 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 \gtrsim 100 M_Earth with periods up to 10 times the period of the inner planet. We also investigate the possible presence of an exomoon on this system and determined 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 case 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 (log R'_hk=-4.95) to a more active (log R'_hk=-4.8) state during the 3 yr monitoring period spanned by the observations. Despite no clear spot crossing has been reported for this system, this analysis claims for a more intensive monitoring of the activity level of this star in order to understand its impact on photometric and radial velocity measurements., MNRAS accepted (14/08/2012)

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.

Context: Several studies have so far placed useful constraints on planetary atmospheric properties using transmission spectrsocopy, and in the case of HD209458b even the radial velocity of the planet during the transit event has been reconstructed opening a new range of possibilities. AIMS. In this contribution we highlight the importance to account for the orbital eccentricity and longitude of periastron of the planetary orbit to accurately interpret the measured planetary radial velocity during the transit. Methods: We calculate the radial velocity of a transiting planet in an eccentric orbit. Given the larger orbital speed of planets with respect to their stellar companions even small eccentricities can result in detectable blue or redshift radial velocity offsets during the transit with respect to the systemic velocity, the exact value depending also on the longitude of the periastron of the planetary orbit. For an hot-jupiter planet, an eccentricity of only e=0.01 can produce a radial velocity offset of the order of the km/s. Conclusions: We propose an alternative interpretation of the recently claimed radial velocity blueshift (~2 km/s) of the planetary spectral lines of HD209458b which implies that the orbit of this system is not exactly circular. In this case, the longitude of the periastron of the stellar orbit is most likely confined in the first quadrant (and that one of the planet in the third quadrant). We highlight that transmission spectroscopy allows not only to study the compositional properties of planetary atmospheres, but also to refine their orbital parameters and that any conclusion regarding the presence of windflows on planetary surfaces coming from transmission spectroscopy measurements requires precise known orbital parameters from RV., Comment: Accepted for publication in A&A Letters

We present new optical long-slit data along 6 position angles of the bulge region of M31. We derive accurate stellar and gas kinematics reaching 5 arcmin from the center, where the disk light contribution is always less than 30%, and out to 8 arcmin along the major axis, where the disk makes 55% of the total light. We show that the velocity dispersions of McElroy (1983) are severely underestimated (by up to 50 km/s) and previous dynamical models have underestimated the stellar mass of M31's bulge by a factor 2. Moreover, the light-weighted velocity dispersion of the galaxy grows to 166 km/s, thus reducing the discrepancy between the predicted and measured mass of the black hole at the center of M31. The kinematic position angle varies with distance, pointing to triaxiality. We detect gas counterrotation near the bulge minor axis. We measure eight emission-corrected Lick indices. They are approximately constant on circles. We derive the age, metallicity and alpha-element overabundance profiles. Except for the region in the inner arcsecs of the galaxy, the bulge of M31 is uniformly old (>12 Gyr, with many best-fit ages at the model grid limit of 15 Gyr), slightly alpha-elements overabundant ([alpha/Fe]~0.2) and at solar metallicity, in agreement with studies of the resolved stellar components. The predicted u-g, g-r and r-i Sloan color profiles match reasonably well the dust-corrected observations. The stellar populations have approximately radially constant mass-to-light ratios (M/L_R ~ 4-4.5 for a Kroupa IMF), in agreement with stellar dynamical estimates based on our new velocity dispersions. In the inner arcsecs the luminosity-weighted age drops to 4-8 Gyr, while the metallicity increases to above 3 times the solar value., Accepted for publication in A&A

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.The Rome Consensus Conference was convened to offer recommendations for clinical practice about the indications and methods of H2-breath testing in gastrointestinal diseases.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.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.

Several nitrofurans and nitroimidazoles have been widely used in veterinary medicine. Some of these compounds are breast carcinogens in rodents and their mechanism of action is hypothesized to be related to reactive metabolites generated by nitroreduction and/or via oxygen-dependent redox cycling. The present work describes the nitroreductive metabolism of nitrofurazone, nitrofurantoin, furazolidone, and metronidazole by the cytosolic and microsomal fractions of mammary tissue from female Sprague-Dawley rats. The data obtained were compared with those obtained with nifurtimox and benznidazole, two well-known rodent carcinogen/mutagens nitroheterocycles. The nitroreductase activity of pure milk xanthine-oxidoreductase (XOR) was evaluated for screening purposes. All the nitrofurans were nitroreduced either by the pure XOR or the cytosolic fraction in the presence of hypoxanthine, and these activities were inhibited by allopurinol. Furthermore, they were nitroreduced by the microsomal fraction in the presence of NADPH, except for the nitrofurazone, suggesting the participation of cytochrome P450 reductase. Nitrofurans metabolism was significantly more intense than that of NFX. No equivalent nitroreductase activity was observed in either subcellular fraction using nitroimidazolic compounds as substrates. These results suggest that the nitroreductive metabolism of nitrofurans and the subsequent redox cycling might be involved in the associated mammary tissue carcinogenic effects. Fil: Bartel, Laura Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. GP. CITEFA - Centro de Investigaciones Toxicológicas (I); Argentina Fil: Montalto, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. GP. CITEFA - Centro de Investigaciones Toxicológicas (I); Argentina Fil: Castro, Jose Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. GP. CITEFA - Centro de Investigaciones Toxicológicas (I); Argentina

Context. We present a photometric and astrometric catalog of 187963 stars located in the field around the old super-metal-rich Galactic open cluster NGC 6253. The total field-of-view covered by the catalog is 34' x 33'. In this field, we provide CCD BVRI photometry. For a smaller region close to the cluster's center, we also provide near-infrared JHK photometry. Aims. We analyze the properties of NGC 6253 by using our new photometric data and astrometric membership. Methods. In June 2004, we targeted the cluster during a 10 day multi-site campaign, which involved the MPG/ESO 2.2m telescope with its wide-field imager and the Anglo-Australian 3.9m telescope, equipped with the IRIS2 near-infrared imager. Archival CCD images of NGC 6253 were used to derive relative proper motions and to calculate the cluster membership probabilities. Results. We have refined the cluster's fundamental parameters, deriving (V_0-M_v)=11.15, E(B - V)=0.15, E(V - I)=0.25, E(V - J)=0.50, and E(V - H)=0.55. The color excess ratios obtained using both the optical and near infrared colors indicate a normal reddening law in the direction of NGC 6253. The age of NGC 6253 at 3.5 Gyr, determined from our best-fitting isochrone appears to be slightly older than the previous estimates. Finally, we estimated the binary fraction among the cluster members to be \sim20%-30% and identified 11 blue straggler candidates., Comment: 16 pages, 13 figures, 11 tables. Accepted for publication in A&A. Catalog avaiable via CDS

RATS is an Italian project devoted to Hot Jupiter search with the transit method. A planet transiting in front of a host star can be mimed by several, and well defined, astrophysical phenomena (Brown, 2003). In order to recognize these false alarms we can utilize a preventive strategy to limit false alarm rates and a spectroscopic follow up to refuse no transit candidates. As preventive strategy it is important to develop an accurate target field selection, with well defined requisites, in order to maximize the solar type star numbers and to minimize the risk of possible astrophysical false alarms.

Food supplementation with Opuntia ficus-indica (OFI) has been associated with a significant reduction in total cholesterol, body fat, hyperglycemia and blood pressure. Since OFI may also have antioxidant and anti-atherogenic properties, we hypothesized that its supplementation might reduce atherogenic lipoproteins, including small, dense low-density lipoproteins (sdLDL). Forty-nine patients (13 men and 36 women, mean age: 56 &plusmn, 5 years) with one or two criteria for the metabolic syndrome weekly consumed 500 g of pasta supplemented with 3% OFI extract (30% of insoluble polysaccharides with high antioxidant power) for 1 month. The full LDL subclass profile was assessed by gel electrophoresis (Lipoprint, Quantimetrix, Redondo Beach, CA, USA). After 1 month of pasta supplementation, waist circumference (p = 0.0297), plasma glucose (p &lt, 0.0001), triglycerides (p = 0.0137), plasma creatinine (p = 0.0244), urea and aspartate transaminase (p &lt, 0.0001 for each) significantly decreased. A percentage increase in larger, less atherogenic LDL-1 (p = 0.0002), with a concomitant reduction in smaller, denser LDL-2 (p &lt, 0.0001) and LDL-3 (p = 0.0004), were found. LDL-4 and-5 decreased, although not significantly. This is the first intervention study suggesting that pasta enriched with an OFI extract may have beneficial effects on some metabolic parameters and the LDL particle sizes, reducing atherogenic sdLDL. Future studies will help to establish if these findings impact cardiovascular outcomes.

OBJECTIVE:\ud We estimated the cost consequence of Italian National Health System (NHS) investment in direct-acting antiviral (DAA) therapy according to hepatitis C virus (HCV) treatment access policies in Italy.\ud \ud METHODS:\ud A multistate, 20-year time horizon Markov model of HCV liver disease progression was developed. Fibrosis stage, age and genotype distributions were derived from the Italian Platform for the Study of Viral Hepatitis Therapies (PITER) cohort. The treatment efficacy, disease progression probabilities and direct costs in each health state were obtained from the literature. The break-even point in time (BPT) was defined as the period of time required for the cumulative costs saved to recover the Italian NHS investment in DAA treatment. Three different PITER enrolment periods, which covered the full DAA access evolution in Italy, were considered.\ud \ud RESULTS:\ud The disease stages of 2657 patients who consecutively underwent DAA therapy from January 2015 to December 2017 at 30 PITER clinical centres were standardized for 1000 patients. The investment in DAAs was considered to equal €25 million, €15 million, and €9 million in 2015, 2016, and 2017, respectively. For patients treated in 2015, the BPT was not achieved, because of the disease severity of the treated patients and high DAA prices. For 2016 and 2017, the estimated BPTs were 6.6 and 6.2 years, respectively. The total cost savings after 20 years were €50.13 and €55.50 million for 1000 patients treated in 2016 and 2017, respectively.\ud \ud CONCLUSIONS:\ud This study may be a useful tool for public decision makers to understand how HCV clinical and epidemiological profiles influence the economic burden of HCV.

Background: Protein induced by vitamin K absence (PIVKA-II), also known as des-gamma-carboxyprothrombin, has been described in relation to HCC being released in association with vitamin K deficiency in the presence of HCC. Serum alpha-fetoprotein (AFP) is the traditional biomarker for HCC detection and follow up but it doesn’t have high sensitivity and specificity. Therefore, there is great interest in identifying new more powerful biomarkers. Materials and methods: One hundred and fourteen subjects were divided into four groups: Group 1 included 58 patients (38M, 20 F) with HCC, mean age 73.5; Group 2 included 38 patients (28M, 10F) with liver cirrhosis (LC), mean age 63.7; Group 3 included 28 control healthy subjects (25M, 3F), mean age 54.7 and Group 4 included 16 HCC patients (8M, 8F) who underwent to TACE as therapy for HCC. PIVKA II levels were dosed in an overnight fasting blood sample with commercially available chemiluminescent assay (Architect 1000i System, Abbott, USA). Statistical analysis: data were expressed as mean ± SD when distribution was normal, otherwise as median (min-max). Student’s t, Mann Whitney U, Chi-square tests and Pearson linear regression analysis were used when appropriate. Results: PIVKA II levels were higher in HCC group (82.3 mAU/ml) with respect to LC (31.5 mAU/ml) and healthy control (19.7 mAU/ml ) groups and in particular HCC vs controls (p