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- ID:
- ivo://CDS.VizieR/J/MNRAS/455/4212
- Title:
- Pan-STARRS 1: occurrence in the Kepler field
- Short Name:
- J/MNRAS/455/4212
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The NASA Kepler mission has revolutionized time-domain astronomy and has massively expanded the number of known extrasolar planets. However, the effect of wide multiplicity on exoplanet occurrence has not been tested with this data set. We present a sample of 401 wide multiple systems containing at least one Kepler target star. Our method uses Pan-STARRS 1 and archival data to produce an accurate proper motion catalogue of the Kepler field. Combined with Pan-STARRS 1 SED fits and archival proper motions for bright stars, we use a newly developed probabilistic algorithm to identify likely wide binary pairs which are not chance associations. As byproducts of this we present stellar SED templates in the Pan-STARRS 1 photometric system and conversions from this system to Kepler magnitudes. We find that Kepler target stars in our binary sample with separations above 6arcsec are no more or less likely to be identified as confirmed or candidate planet hosts than a weighted comparison sample of Kepler targets of similar brightness and spectral type. Therefore we find no evidence that binaries with projected separations greater than 3000au affect the occurrence rate of planets with P<300d around FGK stars.
- ID:
- ivo://CDS.VizieR/J/AJ/162/13
- Title:
- Parameters estimation for 173 eclipsing binaries
- Short Name:
- J/AJ/162/13
- Date:
- 21 Mar 2022 00:50:18
- Publisher:
- CDS
- Description:
- High precision CCD observations of six totally eclipsing contact binaries were presented and analyzed. It is found that only one target is an A-type contact binary (V429Cam), while the others are W-type contact ones. By analyzing the times of light minima, we discovered that two of them exhibit secular period increase while three manifest long-term period decrease. For V1033Her, a cyclic variation superimposed on the long-term increase was discovered. By comparing the Gaia distances with those calculated by the absolute parameters of 173 contact binaries, we found that the Gaia distance can be applied to estimate the absolute parameters for most contact binaries. The absolute parameters of our six targets were estimated using their Gaia distances. The evolutionary status of contact binaries was studied, and we found that the A- and W-subtype contact binaries may have different formation channels. The relationship between the spectroscopic and photometric mass ratios for 101 contact binaries was presented. It was discovered that the photometric mass ratios are in good agreement with the spectroscopic ones for almost all of the totally eclipsing systems, which is corresponding to the results derived by Pribulla et al. and Terrell & Wilson.
- ID:
- ivo://CDS.VizieR/J/ApJS/218/26
- Title:
- Parameters of planets orbiting coolest dwarfs
- Short Name:
- J/ApJS/218/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The coolest dwarf stars targeted by the Kepler Mission constitute a relatively small but scientifically valuable subset of the Kepler target stars, and provide a high-fidelity, nearby sample of transiting planetary systems. Using archival Kepler data spanning the entire primary mission, we perform a uniform analysis to extract, confirm, and characterize the transit signals discovered by the Kepler pipeline toward M-type dwarf stars. We recover all but two of the signals reported in a recent listing from the Exoplanet Archive resulting in 163 planet candidates associated with a sample of 104 low-mass stars. We fitted the observed light curves to transit models using a Markov Chain Monte Carlo method and we have made the posterior samples publicly available to facilitate further studies. We fitted empirical transit times to individual transit signals with significantly non-linear ephemerides for accurate recovery of transit parameters and precise measuring of transit timing variations. We also provide the physical parameters for the stellar sample, including new measurements of stellar rotation, allowing the conversion of transit parameters into planet radii and orbital parameters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/1020
- Title:
- Parent stars of extrasolar planets. XIV.
- Short Name:
- J/MNRAS/446/1020
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of our analysis of new high-resolution spectra of 30 late-F to early-G dwarf field stars for the purpose of deriving their Li abundances. They were selected from the subsample of stars in the Valenti and Fischer compilation that are lacking detected planets. These new data serve to expand our comparison sample used to test whether stars with Doppler-detected giant planets display Li abundance anomalies. Our results continue to show that Li is deficient among stars with planets when compared to very similar stars that lack such planets. This conclusion is strengthened when we add literature data to ours in a consistent way. We present a table of stars with planets paired with very similar stars lacking planets, extending the recent similar results of Delgado Mena et al. (2014A&A...562A..92D, Cat. J/A+A/562/A92).
- ID:
- ivo://CDS.VizieR/J/MNRAS/468/3499
- Title:
- Partially resolved binaries in PS1 data
- Short Name:
- J/MNRAS/468/3499
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using shape measurement techniques developed for weak lensing surveys, we have identified three new ultracool binaries in the Pan-STARRS 1 (Chambers et al., 2016, arXiv:1612.05560, Cat. II/349) survey. Binary companions that are not completely resolved can still alter the shapes of stellar images. These shape distortions can be measured if point spread function anisotropy caused by the telescope is properly accounted for. We show using both a sample of known binary stars and simulated binaries that we can reliably recover binaries wider than around 0.3-arcsec and with flux ratios greater than around 0.1. We then applied our method to a sample of ultracool dwarfs within 30pc with 293 objects having sufficient Pan-STARRS 1 data for our method. In total, we recovered all but one of the 11 binaries wider than 0.3-arcsec in this sample. Our one failure was a true binary detected with a significant but erroneously high ellipticity that led it to be rejected in our analysis. We identify three new binaries, one a simultaneous discovery, with primary spectral types M6.5, L1 and T0.5. These latter two were confirmed with Keck/Near Infrared Camera 2 follow-up imaging. This technique will be useful for identifying large numbers of stellar and substellar binaries in the upcoming Large Synoptic Survey Telescope and Dark Energy Survey sky surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/480/495
- Title:
- Patterns of color variations in close binaries
- Short Name:
- J/A+A/480/495
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first of a series of papers in which we present the results of a long-term photometric monitoring project carried out at Catania Astrophysical Observatory aimed at studying magnetic activity in late-type components of close binary systems, its dependence on global stellar parameters, and its evolution on different time scales from days to years. In this first paper, we present the complete observation dataset and new results of an investigation into the origin of brightness and color variations observed in the well-known magnetically active close binary stars: AR Psc, VY Ari, UX Ari, V711 Tau, EI Eri, V1149 Ori, DH Leo, HU Vir, RS CVn, V775 Her, AR Lac, SZ Psc, II Peg and BY Dra . About 38000 high-precision photoelectric nightly observations in the U, B and V filters are analysed. Correlation and regression analyses of the V magnitude vs. U-B and B-V color variations are carried out and a comparison with model variations for a grid of active region temperature and filling factor values is also performed. We find the existence of two different patterns of color variation. Eight stars in our sample: BY Dr, VY Ari, V775 Her, II Peg, V1149 Ori, HU Vir, EI Eri and DH Leo become redder when they become fainter, as is expected from the presence of active regions consisting of cool spots. The other six stars show the opposite behaviour, i.e. they become bluer when they become fainter. For V711 Tau this behaviour could be explained by the increased relative U- and B- flux contribution by the earlier-type component of the binary system when the cooler component becomes fainter. On the other hand, for AR Psc, UX Ari, RS CVn, SZ Psc and AR Lac the existence of hot photospheric faculae must be invoked. We also found that in single-lined and double-lined binary stars in which the fainter component is inactive or much less active the V magnitude is correlated to B-V and U-B color variations in more than 60% of observation seasons. The correlation is found in less than 40% of observation seasons when the fainter component has a non-negligible level of activity and/or hot faculae are present but they are either spatially or temporally uncorrelated to spots.
- ID:
- ivo://CDS.VizieR/J/ApJ/640/1051
- Title:
- 25pc sample of Sun-like stars
- Short Name:
- J/ApJ/640/1051
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Sun-like stars have stellar, brown dwarf, and planetary companions. To help constrain their formation and migration scenarios, we analyze the close companions (orbital period<5yr) of nearby Sun-like stars. By using the same sample to extract the relative numbers of stellar, brown dwarf, and planetary companions, we verify the existence of a very dry brown dwarf desert and describe it quantitatively.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A25
- Title:
- PDS70 VLT/SPHERE images
- Short Name:
- J/A+A/632/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- PDS 70 is a young (5.4Myr), nearby (~113pc) star hosting a known transition disk with a large gap. Recent observations with SPHERE and NACO in the near-infrared (NIR) allowed us to detect a planetary mass companion, PDS70b, within the disk cavity. Moreover, observations in H{alpha} with MagAO and MUSE revealed emission associated to PDS 70 b and to another new companion candidate, PDS70c, at a larger separation from the star. PDS 70 is the only multiple planetary system at its formation stage detected so far through direct imaging. Our aim is to confirm the discovery of the second planet PDS 70 c using SPHERE at VLT, to further characterize its physical properties, and search for additional point sources in this young planetary system. Methods. We re-analyzed archival SPHERE NIR observations and obtained new data in Y, J, H and K spectral bands for a total of four different epochs. The data were reduced using the data reduction and handling pipeline and the SPHERE data center. We then applied custom routines (e.g. ANDROMEDA and PACO) to subtract the starlight. We re-detect both PDS 70 b and c and confirm that PDS70c is gravitationally bound to the star. We estimate this second planet to be less massive than 5M_Jup_ and with a Teff around 900K. Also, it has a low gravity with log g between 3.0 and 3.5dex. In addition, a third object has been identified at short separation (~0.12") from the star and gravitationally bound to the star. Its spectrum is however very blue, so that we are probably seeing stellar light reflected by dust and our analysis seems to demonstrate that it is a feature of the inner disk. We, however, cannot completely exclude the possibility that it is a planetary mass object enshrouded by a dust envelope. In this latter case, its mass should be of the order of few tens of M_{Earth}_. Moreover, we propose a possible structure for the planetary system based on our data that, however, cannot be stable on a long timescale.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A117
- Title:
- Periods of 2290 CoRoT binaries
- Short Name:
- J/A+A/602/A117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CoRoT mission during its flight-phase 2007-2012 delivered the light-curves for over 2000 eclipsing binaries. Data from the Kepler mission have proven the existence of several transiting circumbinary planets. Albeit light-curves from CoRoT have typically lower precision and shorter coverage, CoRoT's number of targets is similar to Kepler, and some of the known circumbinary planets could potentially be detected in CoRoT data as well. The aim of this work has been a revision of the entire CoRoT data-set for the presence of circumbinary planets, and the derivation of limits to the abundances of such planets. We developed a code which removes the light curve of the eclipsing binaries and searches for quasi-periodic transit-like features in a light curve after removal of binary eclipses and instrumental features. The code needs little information on the sample systems and can be used for other space missions as well, like Kepler, K2, TESS and PLATO. The code is broad in the requirements leading to detections, but was tuned to deliver an amount of detections that is manageable in a subsequent, mainly visual, revision about their nature. In the CoRoT sample we identified three planet candidates whose transits would have arisen from a single pass across the central binary. No candidates remained however with transit events from multiple planetary orbits. We calculated the upper limits for the number of Jupiter, Saturn and Neptune sized planets in co-planar orbits for different orbital period ranges. We found that there are much less giant planets in short-periodic orbits around close binary systems than around single stars.