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301. Lick NPM2 Catalog
ID:
ivo://CDS.VizieR/I/283A
Title:
Lick NPM2 Catalog
Short Name:
I/283A
Date:
21 Oct 2021
Publisher:
CDS
Description:
The NPM2 Catalog is the second part of the Lick Northern Proper Motion (NPM) program to measure absolute proper motions, on an inertial system defined by distant galaxies, for nearly 400,000 stars over a blue apparent magnitude range from 8 to 18. There are 1246 6x6degree fields in the NPM survey (to declination -23 degrees). The NPM2 Catalog covers the 28% of the northern sky lying near the plane of the the Milky Way and contains some 232,000 stars in the 347 NPM fields remaining after the 1993 NPM1 Catalog (149,000 stars in 899 fields away from the Milky Way). Each NPM field was photographed with the 51cm Carnegie Double Astrograph at two epochs between 1947 and 1988. The mean first and second epochs are 1950 and 1977; the average epoch difference is 27 years. The first-epoch plates were taken in the blue only; both blue and yellow plates were taken at the second epoch. For NPM2, the plates were scanned by the Precision Measuring Machine (PMM) at the US Naval Observatory, Flagstaff. From the PMM scans, 120,000 faint (B>14) stars were chosen anonymously for the NPM astrometric reductions and for statistical studies of stellar motions. The NPM2 catalog also contains 92,000 bright (B<14) positional reference stars, mostly from the Tycho-2 Catalogue, and 35,000 stars chosen for astronomical interest from Klemola's "Lick Input Catalog of Special Stars". (These categories overlap). Details of the NPM2 star selection, data reductions, and catalog compilation will be presented in a paper being prepared for the Astronomical Journal. The completed version of the NPM2 Catalog totals 232,062 stars from all 347 NPM2 fields; it supersedes the September 2002 preliminary version (295 fields). Together with the NPM1 Catalog (Cat. I/199, or http://www.ucolick.org/~npm/NPM1/) the NPM2 Catalog completes the Lick Northern Proper Motion program after more than a half-century of work by three generations of Lick Observatory astronomers. The NPM2 catalog gives J2000 positions computed for the catalog epoch 2000, and is ordered in 108 one-degree declination zones from +83 degrees to -23 degrees. Following the convention of the NPM1 catalog, each NPM2 star has an NPM2 "name" (e.g. +83.0001) reflecting the declination zone and a running number in right ascension order within the zone. The NPM2 Catalog is also available as 108 separate files, one for each declination zone from +83 degrees (z+83n) to -23 degrees (z-23n), from http://www.ucolick.org/~npm/NPM2/zones/ Each star's entry includes the absolute proper motion and blue (B) magnitude. For 98.5% of the stars the B-V color is also given. Other data given for each star are: the original mean epoch, a stellar class code, the number of NPM fields on which the star was measured, and discrepancy flags for proper motion, and photometry. Tycho-2 numbers are given for the primary positional reference stars (40% of NPM2); for these stars the Tycho B,V photometry, transformed to Johnson B and B-V, has been averaged with the NPM2 photographic photometry, with appropriate weights. ACRS and Hipparcos numbers are also given for NPM2 stars selected from those catalogs. The RMS precision of the NPM2 individual proper motions is about 0.6"/cent (6mas/yr) in each coordinate, comparable to the NPM1 errors. The NPM2 relative proper motions in each field were reduced to absolute (ICRS system) using an average of 370 Tycho-2 stars per NPM2 field. Magnitude-dependent systematic errors for the brightest (8<B<12) NPM2 stars were removed in the same reductions. The RMS accuracy of the proper motion zero point in each field is about 0.05"/cent (0.5mas/yr) in each coordinate. The RMS position errors at the NPM2 catalog epoch 2000 average about 0.2" (200mas) in each coordinate, due mostly to the accumulated proper motion error from original plate epochs (average 1968) to 2000. The pure positional errors at the original epochs average 0.08" (80mas) in each coordinate. The RMS errors for the NPM photographic photometry average about 0.18mag in B, and 0.20 mag in B-V. We thank the National Science Foundation for its long-term support of the NPM program. The NPM2 phase was supported by NSF grants AST-9530632 and AST-9988105. We thank the Yale Southern Proper Motion group (W. van Altena, I. Platais, and T. Girard) for their help in developing software to process the PMM plate scans.
302. Lick Saturn-Voyager Reference Star Catalogue
ID:
ivo://CDS.VizieR/I/153
Title:
Lick Saturn-Voyager Reference Star Catalogue
Short Name:
I/153
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Lick Saturn-Voyager Reference Star Catalogue contains accurate equatorial coordinates for 4551 stars in a band of sky against which cameras of the Voyager spacecraft were pointed for observations in the region of Saturn during the flyby. All of the reference stars are in the range 12h 40min to 14h 12min in right ascension (1950) and +02deg. to -09deg. in declination. Mean errors of the positions are about 0.25".
303. Light-Motion Curve Catalogue (LMCC) in Stripe 82
ID:
ivo://CDS.VizieR/V/141
Title:
Light-Motion Curve Catalogue (LMCC) in Stripe 82
Short Name:
V/141
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a public archive of light-motion curves in Sloan Digital Sky Survey (SDSS) Stripe 82, covering 99{deg} in right ascension (20.7h to 3.3h) and spanning 2.52{deg} in declination (-1.26 to 1.26), for a total sky area of about 249sq.deg. Stripe 82 has been repeatedly monitored in the u, g, r, i and z bands over a seven-year baseline. Objects are cross-matched between runs, taking into account the effects of any proper motion. The resulting catalogue contains almost 4million light-motion curves of stellar objects and galaxies. The photometry are recalibrated to correct for varying photometric zeropoints, achieving ~20mmag and 30mmag root-mean-square (RMS) accuracy down to 18mag in the g, r, i and z bands for point sources and extended sources, respectively. The astrometry are recalibrated to correct for inherent systematic errors in the SDSS astrometric solutions, achieving 32mas and 35mas RMS accuracy down to 18mag for point sources and extended sources, respectively. For each light-motion curve, 229 photometric and astrometric quantities are derived and stored in a higher-level catalogue. On the photometric side, these include mean exponential and PSF magnitudes along with uncertainties, RMS scatter, {chi}^2^ per degree of freedom, various magnitude distribution percentiles, object type (stellar or galaxy), and eclipse, Stetson and Vidrih variability indices. On the astrometric side, these quantities include mean positions, proper motions as well as their uncertainties and {chi}^2^ per degree of freedom. The here presented light-motion curve catalogue is complete down to r~21.5mag and is at present the deepest large-area photometric and astrometric variability catalogue available.
304. Lists of arm and interarm supernovae
ID:
ivo://CDS.VizieR/J/MNRAS/459/3130
Title:
Lists of arm and interarm supernovae
Short Name:
J/MNRAS/459/3130
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using a sample of 215 supernovae (SNe), we analyse their positions relative to the spiral arms of their host galaxies, distinguishing grand-design (GD) spirals from non-GD (NGD) galaxies. We find that: (1) in GD galaxies, an offset exists between the positions of Ia and core-collapse (CC) SNe relative to the peaks of arms, while in NGD galaxies the positions show no such shifts; (2) in GD galaxies, the positions of CC SNe relative to the peaks of arms are correlated with the radial distance from the galaxy nucleus. Inside (outside) the corotation radius, CC SNe are found closer to the inner (outer) edge. No such correlation is observed for SNe in NGD galaxies nor for SNe Ia in either galaxy class; (3) in GD galaxies, SNe Ibc occur closer to the leading edges of the arms than do SNe II, while in NGD galaxies they are more concentrated towards the peaks of arms. In both samples of hosts, the distributions of SNe Ia relative to the arms have broader wings. These observations suggest that shocks in spiral arms of GD galaxies trigger star formation in the leading edges of arms affecting the distributions of CC SNe (known to have short-lived progenitors). The closer locations of SNe Ibc versus SNe II relative to the leading edges of the arms supports the belief that SNe Ibc have more massive progenitors. SNe Ia having less massive and older progenitors, have more time to drift away from the leading edge of the spiral arms.
305. LMC emission-line stars. Armagh survey
ID:
ivo://CDS.VizieR/J/A+A/555/A141
Title:
LMC emission-line stars. Armagh survey
Short Name:
J/A+A/555/A141
Date:
21 Oct 2021
Publisher:
CDS
Description:
Accurate astrometry is required to reliably cross-match 20th-century photographic catalogues against 21st-century digital surveys. The present work provides modern-area identifications and astrometry for the 801 emission-line objects "of stellar appearance" in the Armagh survey (the largest of its nature to date). Targets have been individually identified in digital images using the Armargh Atlas and, in most cases, unambiguously matched to entries in the UCAC astrometric catalogues.
306. Local structure & star formation history of the MW
ID:
ivo://CDS.VizieR/J/AJ/158/122
Title:
Local structure & star formation history of the MW
Short Name:
J/AJ/158/122
Date:
09 Mar 2022 22:00:00
Publisher:
CDS
Description:
Gaia DR2 (Cat. I/345) provides unprecedented precision in measurements of the distance and kinematics of stars in the solar neighborhood. Through applying unsupervised machine learning on DR2's 5D data set (3D position + 2D velocity), we identify a number of clusters, associations, and comoving groups within 1 kpc and |b|<30{deg} (many of which have not been previously known). We estimate their ages with the precision of ~0.15 dex. Many of these groups appear to be filamentary or string-like, oriented in parallel to the Galactic plane, and some span hundreds of parsec in length. Most of these string lack a central cluster, indicating that their filamentary structure is primordial, rather than the result of tidal stripping or dynamical processing. The youngest strings (<100 Myr) are orthogonal to the Local Arm. The older ones appear to be remnants of several other arm-like structures that cannot be presently traced by dust and gas. The velocity dispersion measured from the ensemble of groups and strings increase with age, suggesting a timescale for dynamical heating of ~300 Myr. This timescale is also consistent with the age at which the population of strings begins to decline, while the population in more compact groups continues to increase, suggesting that dynamical processes are disrupting the weakly bound string populations, leaving only individual clusters to be identified at the oldest ages. These data shed a new light on the local galactic structure and a large-scale cloud collapse.
307. Local velocity substructures in the Milky Way disk
ID:
ivo://CDS.VizieR/J/ApJ/847/123
Title:
Local velocity substructures in the Milky Way disk
Short Name:
J/ApJ/847/123
Date:
21 Oct 2021
Publisher:
CDS
Description:
We confirm, quantify, and provide a table of the coherent velocity substructure of the Milky Way disk within 2kpc of the Sun toward the Galactic anticenter, with a 0.2kpc resolution. We use the radial velocities of ~340000 F-type stars obtained with the Guoshoujing Telescope (also known as the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, LAMOST), and proper motions derived from the PPMXL catalog. The PPMXL proper motions have been corrected to remove systematic errors by subtracting the average proper motions of galaxies and QSOs that have been confirmed in the LAMOST spectroscopic survey, and that are within 2.5{deg} of the star's position. We provide the resulting table of systematic offsets derived from the PPMXL proper motion measurements of extragalactic objects identified in the LAMOST spectroscopic survey. Using the corrected phase-space stellar sample, we find statistically significant deviations in the bulk disk velocity of 20km/s or more in the three-dimensional velocities of Galactic disk stars. The bulk velocity varies significantly over length scales of half a kiloparsec or less. The rotation velocity of the disk increases by 20km/s from the Sun's position to 1.5kpc outside the solar circle. Disk stars in the second quadrant, within 1kpc of the Sun, are moving radially toward the Galactic center and vertically toward a point a few tenths of a kiloparsec above the Galactic plane; looking down on the disk, the stars appear to move in a circular streaming motion with a radius of the order of 1kpc.
308. LOFAR long baselines at 140MHz Calibrators
ID:
ivo://CDS.VizieR/J/A+A/574/A73
Title:
LOFAR long baselines at 140MHz Calibrators
Short Name:
J/A+A/574/A73
Date:
21 Oct 2021
Publisher:
CDS
Description:
An efficient means of locating calibrator sources for international LOw Frequency ARray (LOFAR) is developed and used to determine the average density of usable calibrator sources on the sky for subarcsecond observations at 140MHz. We used the multi-beaming capability of LOFAR to conduct a fast and computationally inexpensive survey with the full international LOFAR array. Sources were preselected on the basis of 325MHz arcminute-scale flux density using existing catalogues. By observing 30 different sources in each of the 12 sets of pointings per hour, we were able to inspect 630 sources in two hours to determine if they possess a sufficiently bright compact component to be usable as LOFAR delay calibrators.
309. Lowell Proper Motion Survey 8991 Northern Stars
ID:
ivo://CDS.VizieR/I/79
Title:
Lowell Proper Motion Survey 8991 Northern Stars
Short Name:
I/79
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalog contains a summary of many individual papers published in the Lowell Observatory Bulletins in the years 1958 to 1970. The data in the machine-readable version include observed positions, proper motions, estimated photographic magnitudes and colors, and references to identifications in other catalogs. Photoelectric data on the UBV system are included for many stars, but no attempt was made to find all existing photometry. The notes.dat file was computerized at the ADC by keying the notes directly to disk storage.
310. Lowell Proper Motion Survey - Southern Hemisphere
ID:
ivo://CDS.VizieR/I/112A
Title:
Lowell Proper Motion Survey - Southern Hemisphere
Short Name:
I/112A
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog contains a summary of the Lowell Proper Motion Survey for the southern hemisphere. The catalog gives the position, motion, magnitude, and color of 2827 stars from the Lowell program.

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