- ID:
- ivo://CDS.VizieR/J/AJ/140/844
- Title:
- UCAC3 proper motion survey
- Short Name:
- J/AJ/140/844
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents 442 new proper motion stellar systems in the southern sky between declinations -90{deg} and -47{deg} with 0.40"/yr>{mu}>=0.18"/yr. These systems constitute a 25.3% increase in new systems for the same region of the sky covered by previous SuperCOSMOS RECONS (SCR) searches that used Schmidt plates as the primary source of discovery. Among the new systems are 25 multiples, plus an additional 7 new common proper motion (CPM) companions to previously known primaries. All stars have been discovered using the third U.S. Naval Observatory (USNO) CCD Astrograph Catalog (UCAC3). A comparison of the UCAC3 proper motions to those from the Hipparcos, Tycho-2, Southern Proper Motion (SPM4), and SuperCOSMOS efforts is presented and shows that UCAC3 provides similar values and precision to the first three surveys.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/745/118
- Title:
- UCAC3 proper motion survey. II. -47<DEC<0{deg}
- Short Name:
- J/ApJ/745/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 474 new proper motion stellar systems (500 objects) in the southern sky having no previously known components, with 0.40"/yr>{mu}>=0.18"/yr between declinations -47{deg} and 0{deg}. In this second paper utilizing the U.S. Naval Observatory third CCD Astrograph Catalog (UCAC3) we complete our sweep of the southern sky for objects in the proper motion range targeted by this survey with R magnitudes ranging from 9.80 to 19.61. The new systems contribute a ~16% increase in the number of new stellar systems for the same region of sky reported in previous SuperCOSMOS Research Consortium On Nearby Stars (RECONS) surveys. Among the newly discovered stellar systems are 16 multiples, plus an additional ten components that are new common proper motion companions to previously known objects. A comparison of UCAC3 proper motions to those from Hipparcos, Tycho-2, Southern Proper Motion, and SuperCOSMOS indicates that all proper motions are consistent to ~10mas/yr, with the exception of SuperCOSMOS. Distance estimates are derived for all stellar systems having SuperCOSMOS Sky Survey B_J_, R_59F_, and I_IVN_ plate magnitudes and Two Micron All Sky Survey (2MASS) infrared photometry. We find five new red dwarf systems estimated to be within 25pc. These discoveries support results from previous proper motion surveys suggesting that more nearby stellar systems are to be found, particularly in the fainter, slower moving samples. In this second paper utilizing the UCAC3 we complete our sweep of the southern sky for objects in the proper motion range targeted by this survey with R magnitudes ranging from 9.80 to 19.61.
- ID:
- ivo://CDS.VizieR/J/MNRAS/422/1495
- Title:
- UKIDSS Galactic Clusters Survey Pleiades members
- Short Name:
- J/MNRAS/422/1495
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a deep wide-field near-infrared survey of the entire Pleiades cluster recently released as part of the UKIRT Infrared Deep Sky Survey (UKIDSS) Galactic Clusters Survey (GCS) Data Release 9 (DR9). We have identified a sample of ~1000 Pleiades cluster member candidates combining photometry in five near-infrared passbands and proper motions derived from the multiple epochs provided by the UKIDSS GCS DR9. We also provide revised membership for all previously published Pleiades low-mass stars and brown dwarfs in the past decade recovered in the UKIDSS GCS DR9 Pleiades survey based on the new photometry and astrometry provided by the GCS.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/3403
- Title:
- UKIDSS-GCS {alpha} Per members
- Short Name:
- J/MNRAS/426/3403
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a deep (J=19.1mag) infrared (ZY JHK) survey over the full {alpha} Per open cluster extracted from the Data Release 9 of the United Kingdom Infrared Telescope Infrared Deep Sky Survey Galactic Clusters Survey (UKIDSS). We have selected ~700 cluster member candidates in ~56 square degrees in {alpha} Per by combining photometry in five near-infrared passbands and proper motions derived from the multiple epochs provided by the UKIDSS Galactic Clusters Survey (GCS) Data Release 9 (DR9). We also provide revised membership for all previously published {alpha} Per low-mass stars and brown dwarfs recovered in GCS based on the new photometry and astrometry provided by DR9.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/3419
- Title:
- UKIDSS GCS Praesepe members
- Short Name:
- J/MNRAS/426/3419
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Over the past decades open clusters have been the subject of many studies. Such studies are crucial considering that the universality of the initial mass function is still a subject of current investigations. Praesepe is an interesting open cluster for the study of the stellar and substellar mass function (MF), considering its intermediate age and its nearby distance. Here we present the results of a wide-field, near-infrared study of Praesepe using the Data Release 9 of the United Kingdom Infrared Telescope Infrared Deep Sky Survey Galactic Clusters Survey. We obtained cluster candidates of Praesepe based on a 3{sigma} astrometric and five-band photometric selection.
- ID:
- ivo://CDS.VizieR/J/MNRAS/431/3222
- Title:
- UKIDSS GCS Upper Sco members
- Short Name:
- J/MNRAS/431/3222
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a proper motion wide-field near-infrared survey of the entire Upper Sco (USco) association (about 160 square degrees) released as part of the UKIRT Infrared Deep Sky (UKIDSS) Galactic Clusters Survey (GCS) Data Release 10 (DR10). We have identified a sample of about 400 astrometric and photometric member candidates combining proper motions and photometry in five near-infrared passbands and another 286 with HK photometry and 2MASS/GCS proper motions. We also provide revised membership for all previously published USco low-mass stars and substellar members based on our selection and identify new candidates, including in regions affected by extinction. We find negligible variability between the two K-band epochs, below the 0.06mag rms level. We estimate an upper limit of 2.2% for wide common proper motions with projected physical separations less than 15000AU. We derive a disk frequency for USco low-mass stars and brown dwarfs between 26 and 37%, in agreement with estimates in IC 348 and sigma Ori. We derive the mass function of the association and find it consistent with the (system) mass function of the solar neighbourhood and other clusters surveyed by the GCS in the 0.2-0.03M_{sun}_ mass range. We confirm the possible excess of brown dwarfs in USco.
- ID:
- ivo://CDS.VizieR/J/MNRAS/394/857
- Title:
- UKIDSS-2MASS proper motion survey
- Short Name:
- J/MNRAS/394/857
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The UK Infrared Telescope Infrared Deep Sky Survey (UKIDSS) is the first of a new generation of infrared surveys. Here, we combine the data from two UKIDSS components, the Large Area Survey (LAS) and the Galactic Cluster Survey (GCS), with Two-Micron All-Sky Survey (2MASS) data to produce an infrared proper motion survey for low-mass stars and brown dwarfs. In total, we detect 267 low-mass stars and brown dwarfs with significant proper motions. We recover all 10 known single L dwarfs and the one known T dwarf above the 2MASS detection limit in our LAS survey area and identify eight additional new candidate L dwarfs. We also find one new candidate L dwarf in our GCS sample. Our sample also contains objects from 11 potential common proper motion binaries. Finally, we test our proper motions and find that while the LAS objects have proper motions consistent with absolute proper motions, the GCS stars may have proper motions which are significantly underestimated. This is possibly due to the bulk motion of some of the local astrometric reference stars used in the proper motion determination.
- ID:
- ivo://CDS.VizieR/J/AJ/136/1290
- Title:
- Ultracool dwarfs from the 2MASS
- Short Name:
- J/AJ/136/1290
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from the 2 Micron All Sky Survey All-Sky Point Source Catalogue, we have extended our census of nearby ultracool dwarfs to cover the full celestial sphere above Galactic latitude of 15{deg}. Starting with an initial catalog of 2139484 sources, we have winnowed the sample to 467 candidate late-type M or L dwarfs within 20pc of the Sun. Fifty-four of those sources already have spectroscopic observations confirming them as late-type dwarfs. We present optical spectroscopy of 376 of the remaining 413 sources, and identify 44 as ultracool dwarfs with spectroscopic distances less than 20pc. Twenty-five of the 37 sources that lack optical data have near-infrared spectroscopy. Combining the present sample with our previous results and data from the literature, we catalog 94 L dwarf systems within 2pc. We discuss the distribution of activity, as measured by H{alpha} emission, in this volume-limited sample. We have coupled the present ultracool catalog with data for stars in the northern 8pc sample and recent (incomplete) statistics for T dwarfs to provide a snapshot of the current 20pc census as a function of spectral type.
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/3966
- Title:
- Ultracool white dwarfs
- Short Name:
- J/MNRAS/449/3966
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present parallax observations and a detailed model atmosphere analysis of 54 cool and ultracool (Teff<4000K) white dwarfs (WDs) in the solar neighbourhood. For the first time, a large number of cool and ultracool WDs have distance and tangential velocities measurements available. Our targets have distances ranging from 21pc to >100pc, and include five stars within 30pc. Contrary to expectations, all but two of them have tangential velocities smaller than 150km/s thus suggesting Galactic disc membership. The oldest WDs in this sample have WD cooling ages of 10Gyr, providing a firm lower limit to the age of the thick disc population. Many of our targets have uncharacteristically large radii, indicating that they are low-mass WDs. It appears that we have detected the brighter population of cool and ultracool WDs near the Sun. The fainter population of ultracool CO-core WDs remain to be discovered in large numbers. The Large Synoptic Survey Telescope should find these elusive, more massive ultracool WDs in the solar neighbourhood.
- ID:
- ivo://CDS.VizieR/J/ApJS/235/6
- Title:
- Updated Multiple Star Catalog (MSC): Sept 2021
- Short Name:
- J/ApJS/235/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog of hierarchical stellar systems with three or more components is an update of the original 1997 version (Tokovinin, 1997-1999, J/A+AS/124/75). For 2000 hierarchies, the new Multiple Star Catalog (MSC) provides distances, component masses and periods, and supplementary information (astrometry, photometry, identifiers, orbits, notes). The MSC content and format are explained, and its incompleteness and strong observational selection are stressed. Nevertheless, the MSC can be used for statistical studies and is a valuable source for planning observations of multiple stars. Rare classes of stellar hierarchies found in the MSC (with six or seven components, extremely eccentric orbits, planar and possibly resonant orbits, hosting planets) are briefly presented. High-order hierarchies have smaller velocity dispersion compared to triples and are often associated with moving groups. The paper concludes with an analysis of the ratio of periods and separations between inner and outer subsystems. In wide hierarchies, the ratio of semimajor axes, estimated statistically, is distributed between 3 and 300, with no evidence of dynamically unstable systems.
