- ID:
- ivo://CDS.VizieR/J/AJ/154/129
- Title:
- PSYM-WIDE: planetary-mass companions to YMG members
- Short Name:
- J/AJ/154/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a direct imaging survey for very large separation (>100 AU), low-mass companions around 95 nearby young K5-L5 stars and brown dwarfs. They are high-likelihood candidates or confirmed members of the young (~<150 Myr) {beta} Pictoris and AB Doradus moving groups (ABDMG) and the TW Hya, Tucana-Horologium, Columba, Carina, and Argus associations. Images in i' and z' filters were obtained with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South to search for companions down to an apparent magnitude of z'~22-24 at separations >~20" from the targets and in the remainder of the wide 5.5'x5.5' GMOS field of view. This allowed us to probe the most distant region where planetary-mass companions could be gravitationally bound to the targets. This region was left largely unstudied by past high-contrast imaging surveys, which probed much closer-in separations. This survey led to the discovery of a planetary-mass (9-13 M_Jup_) companion at 2000 AU from the M3V star GU Psc, a highly probable member of ABDMG. No other substellar companions were identified. These results allowed us to constrain the frequency of distant planetary-mass companions (5-13 M_Jup_) to 0.84_-0.66_^+6.73^% (95% confidence) at semimajor axes between 500 and 5000 AU around young K5-L5 stars and brown dwarfs. This is consistent with other studies suggesting that gravitationally bound planetary-mass companions at wide separations from low-mass stars are relatively rare.
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- ID:
- ivo://CDS.VizieR/I/290
- Title:
- Pulkovo catalogue of 58483 stars (Pul-3)
- Short Name:
- I/290
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalogue of positions and proper motions of 58483 stars (Pul-3) has been constructed at the Pulkovo observatory. The Pul-3 is based on the results of measurements of the photographic plates ((x,y)-data) with galaxies (Deutsch's plan). The observations were made with Pulkovo Normal Astrograph (F=3467mm, D=330mm) during the periods from 1935 till 1960 (the first epoch) and from 1969 till 1986 (the second epoch). The radius of working field was 50 arcmin for all plates. The exposure times were 1 hour. All plates were taken near the meridian. The measurements of the plates were made at the Pulkovo observatory in 1970-s and in 1980-s with ASCORECORD measuring machine. Photographic magnitudes of these stars have been determined at the Pulkovo observatory. The Pulkovo plates contain stars mainly 12-16.5 magnitudes in 146 field in declination zone from -5 to +85 degrees. The maximal density of stars in the Pulkovo plates is 500 stars per square degree. The Tycho-2 catalogue (Cat. <I/259>) has been used as a reference catalogue for astrometric reductions of the photographic plates. The great stars density of the Tycho-2 provides 40-65 reference stars in working field of the Pulkovo plates. Only approximate equatorial coordinates of the optical centers of all plates had been known in initial stage of construction of the Pul-3 catalogue and thus recalculation of ones has been done. A six-parameter plate model has been used for the astrometric reduction of the plates. The residuals of the tangential coordinates of reference stars have been analysed to investigate residual systematic errors. The coma parameters have been determined and coma-dependent systematic errors have been excluded. The magnitude-dependent systematic errors and color-dependent ones were investigated. The most significant corrections for magnitude equation have been obtained for stars brighter than 9 magnitude and fainter than 14 magnitude. The most significant color corrections have been obtained in equatorial zone for declinations of stars. The corrected coordinates of all stars have been determined. On the whole, recalculation of the plates optical centers and taking into account of all revealed systematic errors provide improvement of the accuracy of coordinates of stars on 64mas and 51mas for right ascension and declination correspondingly. The new proper motions have been determined for all stars. The mean position has been calculated at the mean epoch of observations of each star using it proper motion. The mean epoch of the Pul-3 is 1963.25. The internal positional accuracy of the Pul-3 catalogue at the mean epoch of observations is 80mas. The internal accuracy of the proper motions is 5mas/yr. Comparisons of the Pul-3 with Tycho-2 and ARIHIP have been done. The Pul-3 external positional accuracy relative to Tycho-2 is 150mas at the mean epoch of the Pulovo plates. The Pul-3 catalogue successfully represents the Tycho-2 system for more than 50000 stars which are fainter than 12 magnitude in 146 fields. The stars from the Pul-3 catalogue may be used as reference stars for reductions of the positional CCD-observations of the extragalactic radio sources and small bodies of the Solar system. The 40-years difference between Pul-3 observational epoch and modern epoch will allow to determine high precision proper motions of the faint stars of the Pul-3 catalogue (about 2mas/yr-3mas/yr). Proper motions of stars from Pul-3 catalogue may be used for stellar kinematics investigations. There are two data files for user's convenience: - the file pul3.dat represents the Pul-3 catalogue; - the file centers.dat contains the equatorial coordinates of centers of the Pulkovo fields (RA, DE).
- ID:
- ivo://CDS.VizieR/J/A+A/618/A144
- Title:
- QSO candidates catalog with APOP & ALLWISE (QCC)
- Short Name:
- J/A+A/618/A144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Quasars are spatially stationary, and they are essential objects in astrometry when defining reference frames. However, the census of quasars is far from complete. Mid-infared colors can be used to find quasar candidates because AGNs show a peculiar appearance in mid-infrared color, but these methods are incapable of separating quasars from AGNs.The aim of our study is to use astrometric and mid-infrared methods to select quasars and get a reliable quasar candidates catalog. We used a near-zero proper motion criterion in conjuction with WISE (all-sky Wide-field Infrared Survey Explorer) [W1-W2] color to select quasar candidates. The [W1-W2] color criterion is defined by the linear boundary of two samples: LAMOST DR5 quasars, which serve as the quasar sample, and LAMOST DR5 stars/galaxies, which serve as the non-quasar sample. The contamination and completeness are evaluated. We present a catalog of 662753 quasar candidates, with a completeness of about 75% and a reliability of 77.2%.
- ID:
- ivo://CDS.VizieR/J/A+A/430/165
- Title:
- Radial velocities for 6691 K and M giants
- Short Name:
- J/A+A/430/165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The table provides Hipparcos positions, Hipparcos & Tycho-2 proper motions, and CORAVEL radial velocities for 6691 K and M giants in the solar neighbourhood, mostly from the Hipparcos survey. A bayesian maximum-likelihood approach has been used to derive the distances and space velocities. New V-I indices, computed from a color transformation based on Hp-V_T2_, are also provided. Spectroscopic binaries have been identified as well. These data may be used to study the kinematics of giant stars in the solar neighbourhood, and to correlate it with their location in the Hertzsprung-Russell diagram.
- ID:
- ivo://CDS.VizieR/J/A+A/546/A61
- Title:
- Radial velocities for XHIP catalogue
- Short Name:
- J/A+A/546/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hundred-Thousand-Proper-Motion (HTPM) project will determine the proper motions of ~113500 stars using a ~23-year baseline. The proper motions will be based on space-based measurements exclusively, with the Hipparcos data, with epoch 1991.25, as first epoch and with the first intermediate-release Gaia astrometry, with epoch ~2014.5, as second epoch. The expected HTPM proper-motion standard errors are 30-190{mu}as/yr, depending on stellar magnitude. Depending on the astrometric characteristics of an object, in particular its distance and velocity, its radial velocity can have a significant impact on the determination of its proper motion. The impact of this perspective acceleration is largest for fast-moving, nearby stars. Our goal is to determine, for each star in the Hipparcos catalogue, the radial-velocity standard error that is required to guarantee a negligible contribution of perspective acceleration to the HTPM proper-motion precision.
- ID:
- ivo://CDS.VizieR/J/PASP/117/1
- Title:
- Radial velocities of 166 LHS stars
- Short Name:
- J/PASP/117/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 178 radial velocity measurements for 166 late-type stars selected from the Luyten Half-Second (LHS) proper motion catalog (Cat. <I/87>). Space velocities are given for all but two of them. Most of the stars lie within 25pc of the Sun, but the list includes a handful of high-velocity transients from the halo population.
- ID:
- ivo://CDS.VizieR/J/AJ/145/134
- Title:
- Radial velocities of 108 stars in Ruprecht 147
- Short Name:
- J/AJ/145/134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ruprecht 147 is a hitherto unappreciated open cluster that holds great promise as a standard in fundamental stellar astrophysics. We have conducted a radial velocity survey of astrometric candidates with Lick, Palomar, and MMT observatories and have identified over 100 members, including 5 blue stragglers, 11 red giants, and 5 double-lined spectroscopic binaries (SB2s). We estimate the cluster metallicity from spectroscopic analysis, using Spectroscopy Made Easy (SME), and find it to be [M/H]=+0.07+/-0.03. We have obtained deep CFHT/MegaCam g'r'i'z' photometry and fit Padova isochrones to the (g'-i') and Two Micron All Sky Survey (J-K_S_) color-magnitude diagrams, using the {tau}^2^ maximum-likelihood procedure of Naylor, and an alternative method using two-dimensional cross-correlations developed in this work. We find best fits for Padova isochrones at age t=2.5+/-0.25Gyr, m-M=7.35+/-0.1, and A_V_=0.25+/-0.05, with additional uncertainty from the unresolved binary population and possibility of differential extinction across this large cluster. The inferred age is heavily dependent on our choice of stellar evolution model: fitting Dartmouth and PARSEC models yield age parameters of 3Gyr and 3.25Gyr, respectively. At ~300pc and ~3Gyr, Ruprecht 147 is by far the oldest nearby star cluster.
- ID:
- ivo://CDS.VizieR/III/239
- Title:
- Radial Velocities with Astrometric Data
- Short Name:
- III/239
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue of radial velocities of Galactic stars with high precision astrometric data (CRVAD) is the result of a merging of star lists from the General Catalog of Mean Radial Velocities (GCRV, Cat. III/213) and from the All-sky Compiled Catalogue of 2.5 Million Stars (ASCC-2.5, Cat. I/280). The cross identification of GCRV and ASCC-2.5 objects was carried out with help of coordinate, magnitude, colour and/or spectral type criteria. Data from the Catalogue of Components of Double and Multiple Stars (CCDM, Cat. I/274) were taken into account for the identification of multiple system components. 34553 stars of the ASCC-2.5 were identified with 33509 stars of the GCRV, i.e. 33509 stars of the GCRV have one entry in the ASCC-2.5, and 1044 objects have two entries. The catalogue includes accurate equatorial coordinates J2000, proper motions and trigonometric parallaxes in the Hipparcos system, B and V magnitudes in Johnson system, spectral classes, multiplicity and variability flags from the ASCC-2.5, and radial velocities, stellar magnitudes and spectra from the GCRV. Stars are sorted in right ascension J2000 order. 3967 stars were selected as radial velocity standard candidates (file rv_std.dat). These stars: - do not have any multiplicity and/or variability flags both in the GCRV and ASCC-2.5; - have standard errors of equatorial coordinates e <= 40 mas; - have standard errors of proper motions e_pm <= 4 mas/yr; - have standard errors of V magnitude e_V <= 0.05 mag and (B-V) colour e_(B-V) <= 0.07 mag; - have standard errors of radial velocity e_RV <= 2 km/s or quality index A or B, which corresponds to e_RV 0.74 and 1.78 km/s; - have at least four RV observations N_RV.
- ID:
- ivo://CDS.VizieR/J/PASP/118/1238
- Title:
- Radial velocity curve of RBS 490
- Short Name:
- J/PASP/118/1238
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- RBS (ROSAT Bright Source) 0490 is a cataclysmic variable star (CV) with unusually strong emission lines. The strength of the emission lines has led to a suggestion that the object is intrinsically faint and correspondingly nearby (33pc), which, if true, would strongly affect estimates of the CV space density. Here we report astrometry, filter photometry, and time-series spectroscopy of this object. The astrometry gives an absolute parallax of 4.5+/-1.5mas and a relative proper motion of 102mas/yr. A Bayesian procedure gives a very uncertain distance estimate of d~300pc, and the small parallax alone implies d>133pc (at 2 standard deviations). The mean V magnitude is 17.4, which implies M_V_=10.9-5log[d/(200pc)], neglecting extinction. At 200pc, the space velocity would be over 90km/s with respect to the local standard of rest. The time-series spectroscopy shows a possible emission-line radial velocity period near 46 minutes. This would be unusually short for an orbital period, and it may represent some other clock in the system.
- ID:
- ivo://CDS.VizieR/J/ApJ/701/1922
- Title:
- Radio interferometric planet search. I.
- Short Name:
- J/ApJ/701/1922
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radio astrometry of nearby, low-mass stars has the potential to be a powerful tool for the discovery and characterization of planetary companions. We present a Very Large Array survey of 172 active M dwarfs at distances of less than 10pc. Twenty-nine stars were detected with flux densities greater than 100uJy. We observed seven of these stars with the Very Long Baseline Array at milliarcsecond resolution in three separate epochs. With a detection threshold of 500uJy in images of sensitivity 1{sigma}~100uJy, we detected three stars three times (GJ 65B, GJ 896A, GJ 4247), one star twice (GJ 285), and one star once (GJ 803). Two stars were undetected (GJ 412B and GJ 1224). For the four stars detected in multiple epochs, residuals from the optically determined apparent motions have an root-mean-square deviation of ~0.2 milliarcseconds, consistent with statistical noise limits. Combined with previous optical astrometry, these residuals provide acceleration upper limits that allow us to exclude planetary companions more massive than 3-6M_Jup_ at a distance of ~1AU with a 99% confidence level.
