- ID:
- ivo://CDS.VizieR/III/254
- Title:
- 2nd Cat. of Radial Velocities with Astrometric Data
- Short Name:
- III/254
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue of radial velocities of Galactic stars with high precision astrometric data, 2nd version (CRVAD-2), is the result of a merging of star lists from the All-Sky Compiled Catalogue of 2.5 Million Stars (ASCC-2.5, Cat. I/280) with the General Catalogue of Radial Velocities (GCRV, Cat. III/213) and with other recently published radial velocity lists and catalogues. Cross identification of 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. Altogether 54907 stars from the ASCC-2.5 were identified with 51762 stars from the RV source catalogues, 3085 stars have secondary components and 30 stars have 3rd components in multiple systems. The CRVAD-2 includes accurate J2000 equatorial coordinates, proper motions and trigonometric parallaxes in the Hipparcos system, Johnson's BV photometric data, spectral types, radial velocities, multiplicity and variability flags. Stars are sorted in the order of increasing right ascension J2000. This catalogue supersedes the previous version numbered <III/239>.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/153/25
- Title:
- Near-infrared observations of 84 KOI systems
- Short Name:
- J/AJ/153/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determine probabilities of physical association for stars in blended Kepler Objects of Interest (KOIs), and find that 14.5%_-3.4%_^+3.8%^ of companions within ~4'' are consistent with being physically unassociated with their primary. This produces a better understanding of potential false positives in the Kepler catalog and will guide models of planet formation in binary systems. Physical association is determined through two methods of calculating multi-band photometric parallax using visible and near-infrared adaptive optics observations of 84 KOI systems with 104 contaminating companions within ~4''. We find no evidence that KOI companions with separations of less than 1'' are more likely to be physically associated than KOI companions generally. We also reinterpret transit depths for 94 planet candidates, and calculate that 2.6%+/-0.4% of transits have R>15R_{oplus}_, which is consistent with prior modeling work.
- ID:
- ivo://CDS.VizieR/J/ApJ/637/1067
- Title:
- Near-IR spectral classification of T dwarfs
- Short Name:
- J/ApJ/637/1067
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A revised near-infrared classification scheme for T dwarfs is presented, based on and superseding prior schemes developed by Burgasser and coworkers (2002ApJ...564..421B) and Geballe and coworkers (2002ApJ...564..466G), and defined following the precepts of the MK process. Drawing from two large spectroscopic libraries of T dwarfs identified largely in the Sloan Digital Sky Survey and the Two Micron All Sky Survey, nine primary spectral standards and five alternate standards spanning spectral types T0-T8 are identified that match criteria of spectral character, brightness, absence of a resolved companion, and accessibility from both the Northern and Southern Hemispheres.
- ID:
- ivo://CDS.VizieR/J/AJ/144/99
- Title:
- Near-IR spectroscopy of 36 late M dwarfs
- Short Name:
- J/AJ/144/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of 36 late M dwarfs obtained with the KeckII/NIRSPEC in the J band at a resolution of ~20000. We have measured projected rotational velocities, absolute radial velocities, and pseudo-equivalent widths of atomic lines. Twelve of our targets did not have previous measurements in the literature. For the other 24 targets, we confirm previously reported measurements. We find that 13 stars from our sample have vsini below our measurement threshold (12km/s) whereas four of our targets are fast rotators (vsini>30km/s). As fast rotation causes spectral features to be washed out, stars with low projected rotational velocities are sought for radial velocity surveys. At our intermediate spectral resolution, we have confirmed the identification of neutral atomic lines reported in McLean et al. We also calculated pseudo-equivalent widths of 12 atomic lines. Our results confirm that the pseudo-equivalent width of KI lines is strongly dependent on spectral types. We observe that the pseudo-equivalent width of FeI and MnI lines remains fairly constant with later spectral type. We suggest that these lines are particularly suitable for deriving metallicities for late M dwarfs.
- ID:
- ivo://CDS.VizieR/J/ApJ/817/112
- Title:
- NEOWISE/AllWISE high proper motion objects
- Short Name:
- J/ApJ/817/112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Wide-field Infrared Survey Explorer (WISE) was reactivated in 2013 December (NEOWISE) to search for potentially hazardous near-Earth objects. We have conducted a survey using the first sky pass of NEOWISE data and the AllWISE catalog to identify nearby stars and brown dwarfs with large proper motions ({mu}_total_>~250mas/yr). A total of 20548 high proper motion objects were identified, 1006 of which are new discoveries. This survey has uncovered a significantly larger sample of fainter objects (W2>~13mag) than the previous WISE motion surveys of Luhman (2014, J/ApJ/781/4) and Kirkpatrick et al. (2014, J/ApJ/783/122). Many of these objects are predicted to be new L and T dwarfs based on near- and mid-infrared colors. Using estimated spectral types along with distance estimates, we have identified several objects that likely belong to the nearby solar neighborhood (d<25pc). We have followed up 19 of these new discoveries with near-infrared or optical spectroscopy, focusing on potentially nearby objects, objects with the latest predicted spectral types, and potential late-type subdwarfs. This subset includes six M dwarfs, five of which are likely subdwarfs, as well as eight L dwarfs and five T dwarfs, many of which have blue near-infrared colors. As an additional supplement, we provide 2MASS and AllWISE positions and photometry for every object found in our search, as well as 2MASS/AllWISE calculated proper motions.
- ID:
- ivo://CDS.VizieR/J/AJ/159/63
- Title:
- New AO obs. of exoplanets & brown dwarf companions
- Short Name:
- J/AJ/159/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The orbital eccentricities of directly imaged exoplanets and brown dwarf companions provide clues about their formation and dynamical histories. We combine new high-contrast imaging observations of substellar companions obtained primarily with Keck/NIRC2 together with astrometry from the literature to test for differences in the population-level eccentricity distributions of 27 long-period giant planets and brown dwarf companions between 5 and 100au using hierarchical Bayesian modeling. Orbit fits are performed in a uniform manner for companions with short orbital arcs; this typically results in broad constraints for individual eccentricity distributions, but together as an ensemble, these systems provide valuable insight into their collective underlying orbital patterns. The shape of the eccentricity distribution function for our full sample of substellar companions is approximately flat from e=0-1. When subdivided by companion mass and mass ratio, the underlying distributions for giant planets and brown dwarfs show significant differences. Low mass ratio companions preferentially have low eccentricities, similar to the orbital properties of warm Jupiters found with radial velocities and transits. We interpret this as evidence for in situ formation on largely undisturbed orbits within massive extended disks. Brown dwarf companions exhibit a broad peak at e~0.6-0.9 with evidence for a dependence on orbital period. This closely resembles the orbital properties and period-eccentricity trends of wide (1-200au) stellar binaries, suggesting that brown dwarfs in this separation range predominantly form in a similar fashion. We also report evidence that the "eccentricity dichotomy" observed at small separations extends to planets on wide orbits: the mean eccentricity for the multi-planet system HR8799 is lower than for systems with single planets. In the future, larger samples and continued astrometric orbit monitoring will help establish whether these eccentricity distributions correlate with other parameters such as stellar host mass, multiplicity, and age.
- ID:
- ivo://CDS.VizieR/J/AJ/154/195
- Title:
- New binaries in the {epsilon} Cha association
- Short Name:
- J/AJ/154/195
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Adaptive Optics-aided speckle observations of 47 young stars in the {epsilon} Cha association made at the 4 m Southern Astrophysical Research Telescope in the I-band. We resolved 10 new binary pairs, 5 previously known binaries, and 2 triple systems, also previously known. In the separation range between 4 and 300 au, the 30 association members of spectral types G0 and later host 6 binary companions, leading to the raw companion frequency of 0.010+/-0.04 per decade of separation, comparable to the main sequence dwarfs in the field. On the other hand, all five massive association members of spectral types A and B have companions in this range. We discuss the newly resolved and known binaries in our sample. Observed motions in the triple system {epsilon} Cha, composed of three similar B9V stars, can be described by tentative orbits with periods 13 and ~900 years and a large mutual inclination.
- ID:
- ivo://CDS.VizieR/J/AJ/145/132
- Title:
- New catalog of 1578 {delta} Scuti stars
- Short Name:
- J/AJ/145/132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present statistical characteristics of 1578 {delta} Scuti stars including nearby field stars and cluster member stars within the Milky Way. We obtained 46% of these stars (718 stars) from work by Rodriguez and collected the remaining 54% of stars (860 stars) from other literature. We updated the entries with the latest information of sky coordinates, color, rotational velocity, spectral type, period, amplitude, and binarity. The majority of our sample is well characterized in terms of typical period range (0.02-0.25days), pulsation amplitudes (<0.5mag), and spectral types (A-F type). Given this list of {delta} Scuti stars, we examined relations between their physical properties (i.e., periods, amplitudes, spectral types, and rotational velocities) for field stars and cluster members, and confirmed that the correlations of properties are not significantly different from those reported in Rodriguez's work. All the {delta} Scuti stars are cross-matched with several X-ray and UV catalogs, resulting in 27 X-ray and 41 UV-only counterparts. These counterparts are interesting targets for further study because of their uniqueness in showing {delta} Scuti-type variability and X-ray/UV emission at the same time. The compiled catalog can be accessed through the Web interface http://stardb.yonsei.ac.kr/DeltaScuti.
- ID:
- ivo://CDS.VizieR/J/AJ/153/218
- Title:
- New IR photometric study of Ap and Am stars
- Short Name:
- J/AJ/153/218
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, 426 well known confirmed Ap and Am stars are photometrically studied in the infrared. The 2MASS, Wide-field Infrared Survey Explorer (WISE), and IRAS data are employed to make analyses. The results in this paper have shown that in the 1-3 {mu}m region over 90% Ap and Am stars have no or little infrared excesses, and infrared radiations in the near-infrared from these stars are probably dominated by the free-free emissions. It is also shown that in the 3-12 {mu}m region, the majority of Ap stars and Am stars have very similar behavior, i.e., in the W1-W2 (3.4-4.6 {mu}m) region, over half of Ap and Am stars have clear infrared excesses, which are possibly due to the binarity, the multiplicity, and/or the debris disk, but in the W2-W3 (4.6-12 {mu}m) region they have no or little infrared excess. In addition, in the 12-22 {mu}m region, some of Ap stars and Am stars show the infrared excesses and infrared radiations for these Ap and Am stars are probably due to the free-free emissions. In addition, it is seen that the probability of being the binarity, the multiplicity and/or the debris disk for Am stars is much higher than that for Ap stars. Furthermore, it can be seen that, in general, no relations can be found between infrared colors and spectral types either for Ap stars or for Am stars.
- ID:
- ivo://CDS.VizieR/J/AJ/131/2722
- Title:
- New L and T dwarfs from the SDSS
- Short Name:
- J/AJ/131/2722
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared observations of 71 newly discovered L and T dwarfs, selected from imaging data of the Sloan Digital Sky Survey (SDSS) using the i-dropout technique. Sixty-five of these dwarfs have been classified spectroscopically according to the near-infrared L dwarf classification scheme of Geballe et al. (2002ApJ...564..466G) and the unified T dwarf classification scheme of Burgasser et al. (2006, Cat. <J/ApJ/637/1067>). The spectral types of these dwarfs range from L3 to T7 and include the latest types yet found in the SDSS. Six of the newly identified dwarfs are classified as early to mid-L dwarfs according to their photometric near-infrared colors, and two others are classified photometrically as M dwarfs. We also present new near-infrared spectra for five previously published SDSS L and T dwarfs, and one L dwarf and one T dwarf discovered by Burgasser et al. (2006, Cat. <J/ApJ/637/1067>) from the Two Micron All Sky Survey. The new SDSS sample includes 27 T dwarfs and 30 dwarfs with spectral types spanning the complex L-T transition (L7-T3).
