- ID:
- ivo://CDS.VizieR/J/AJ/117/1375
- Title:
- Orion Trapezium cluster
- Short Name:
- J/AJ/117/1375
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have imaged an area ~5arcmin^2^ at the center of the Trapezium cluster in Orion in the K band using the University of Hawaii (UH) adaptive optics system at the UH 2.2 m telescope. Our survey detects 292 stars brighter than K=18.2mag and resolves pairs to the 0.23" diffraction limit of the telescope. The binary fraction in the angular separation range 0.3"-0.6", corresponding to 132-264AU at 440pc, is indistinguishable from that of the solar-like stars in the solar neighborhood. Proplyds are associated with both single stars and visual binaries. About half the stars in our sample have also been measured at V and I by Prosser et al. (1994ApJ...421..517P); most of these seem to be about 10^6^yr old, observed through moderate extinction, and having some excess emission at K. The luminosity function turns over before the stellar limit of ~13.5mag, indicating that the cluster does not contain a large population of massive brown dwarfs.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/703/L99
- Title:
- Outlandish orbit of HAT-P-7b
- Short Name:
- J/ApJ/703/L99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We show that the exoplanet HAT-P-7b has an extremely tilted orbit, with a true angle of at least 86{deg} with respect to its parent star's equatorial plane, and a strong possibility of retrograde motion. We also report evidence for an additional planet or companion star. The evidence for the unparalleled orbit and the third body is based on precise observations of the star's apparent radial velocity (RV). The anomalous RV due to rotation (the Rossiter-McLaughlin effect) was found to be a blueshift during the first half of the transit and a redshift during the second half, an inversion of the usual pattern, implying that the angle between the sky-projected orbital and stellar angular momentum vectors is 182.5{deg}+/-9.4{deg}. The third body is implicated by excess RV variation of the host star over 2yr. Some possible explanations for the tilted orbit of HAT-P-7b are a close encounter with another planet, the Kozai effect, and resonant capture by an inward-migrating outer planet.
- ID:
- ivo://CDS.VizieR/J/A+A/587/A51
- Title:
- Overlooked wide companions of nearby F stars
- Short Name:
- J/A+A/587/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We checked a sample of 545 F stars within 50pc for wide companions using existing near-infrared and optical sky surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/883/105
- Title:
- PA & angular separation measurements of 80 Tau
- Short Name:
- J/ApJ/883/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The empirical mass-luminosity relation in the Hyades cluster rests on dynamical mass determinations for five binary systems, of which one is eclipsing and the other four are visual or interferometric binaries. The last one was identified and first measured more than 20yr ago. Here we present dynamical mass measurements for a new binary system in the cluster, 80 Tau, which is also a visual pair with a much longer orbital period of about 170yr. Although we lack the radial-velocity information that has enabled the individual mass determinations in all of the previous binaries, we show that it is still possible to derive the component masses for 80 Tau using only astrometric observations. This is enabled by the accurate proper motion measurements from the Hipparcos and Gaia missions, which constrain the orbital acceleration in the plane of the sky. Separate proper motion values from Gaia for the primary and secondary provide a direct constraint on the mass ratio. Our mass measurements, M_A_=1.63_-0.13_^+0.30^M_{sun}_ and M_B_=1.11_-0.14_^+0.21^M_{sun}_, are consistent with the mass-luminosity relation defined by the five previously known systems, which in turn is in good agreement with current models of stellar evolution.
- ID:
- ivo://CDS.VizieR/J/AJ/128/3019
- Title:
- Pal 13 blue stragglers and main-sequence binaries
- Short Name:
- J/AJ/128/3019
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-precision VI photometry of stars from the middle of the giant branch to about 5mag below the main-sequence turnoff in the globular cluster Palomar 13 based on images obtained with the Keck II 10m telescope. We tabulate a complete sample of blue stragglers in the cluster out to about 18 core radii.
- 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.
