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581. The AC2000 Catalogue
ID:
ivo://CDS.VizieR/I/247
Title:
The AC2000 Catalogue
Short Name:
I/247
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Astrographic Catalogue (AC) was an international effort designed to photograph and measure the positions of all stars brighter than magnitude 11.0. In total, some 4.6 million stars were observed, many as faint as 13th magnitude. Users should realize that a few thousand of the brightest stars are not included; their images on the source plates were grossly over-exposed and therefore measurements were often not made. This project was started over 100 years ago, and the positions that have been derived from the AC data are being used, in combination with modern epoch positions, to determine accurate proper motions. The United States Naval Observatory has completed the reductions of the Astrographic Catalogue data (AC) to a consistent system. The resulting catalog, called AC 2000, contains 4,621,836 stars covering the entire sky, at an average epoch of 1907. The positions are on the Hipparcos reference frame (J2000.0) at the epochs of observation. Each of the 22 zones making up the Astrographic Catalogue was reduced independently using the Astrographic Catalog Reference Stars (ACRS). Each was analyzed for tilt, radial and tangential distortions, coma, magnitude equation and non-symmetric field distortions. Following these reductions, the data were placed on the Hipparcos system and the magnitudes were converted to be close to that of the Tycho B data. The resulting data were then combined into the final catalog. Detailed information on the reduction methodology and input data can be found in the file "intro.tex", or in the postscript documents provided provided in the "ps" subdirectory. The data contain the positions (eq. J2000.0) at mean epochs of observation, magnitude estimates and accuracy estimates for each star. Cross identifications with the Hipparcos Catalogue, Tycho Catalogue and the Astrographic Catalog Reference Stars are provided to facilitate future work with these stars. Interested parties are encouraged to visit the AC web site at http://aries.usno.navy.mil/ad/ac.html.
582. The ACT Reference Catalog
ID:
ivo://CDS.VizieR/I/246
Title:
The ACT Reference Catalog
Short Name:
I/246
Date:
21 Oct 2021
Publisher:
CDS
Description:
The U.S. Naval Observatory has completed the compilation of the ACT Reference Catalog, containing 988,758 stars covering the entire sky. The motivation behind the ACT was to provide accurate proper motions for the majority of the stars in the Tycho Catalogue (ESA SP-1200). To do this, positions from new reductions of the Astrographic Catalogue (AC 2000) were combined with those of Tycho. The large epoch span between the two catalogs yields proper motions about an order of magnitude more accurate than those published in the Tycho Catalogue. The astrometric data contained in the ACT Reference Catalog include positions, proper motions and error estimates. These are on the Hipparcos System (J2000.0) for epoch J2000.0. Photometric data (B and V) from Tycho are included. Additionally, cross references to the Tycho, AC 2000, Bonner Durchmusterung (BD), Cordoba Durchmusterung (CD), Cape Durchmusterung (CPD), Henry Draper (HD) and Hipparcos Catalogues are given.
583. The AMIGA project. Revised positions for CIG galaxies
ID:
ivo://CDS.VizieR/J/A+A/411/391
Title:
The AMIGA project. Revised positions for CIG galaxies
Short Name:
J/A+A/411/391
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present revised positions for the 1051 galaxies belonging to the Karachentseva Catalog of Isolated Galaxies (CIG, Cat. <VII/82>). New positions were calculated by applying SExtractor to the Digitized Sky Survey CIG fields with a spatial resolution of 1.2". We visually checked the results and for 118 galaxies had to recompute the assigned positions due to complex morphologies (e.g. distorted isophotes, undefined nuclei, knotty galaxies) or the presence of bright stars. We found differences between older and newer positions of up to 38" with a mean value of 2.96" relative to SIMBAD and up to 38" and 2.42" respectively relative to UZC (Cat. <J/PASP/111/438>). Based on star positions from the APM catalog (Cat. <I/267>) we determined that the DSS astrometry of five CIG fields has a mean offset in ({alpha},{delta}) of (-0.90", 0.93") with a dispersion of 0.4". These results have been confirmed using the 2MASS All-Sky Catalog of Point Sources (Cat. <II/246>). The intrinsic errors of our method combined with the astrometric ones are of the order of 0.5".
584. The APM-North Catalogue
ID:
ivo://CDS.VizieR/I/267
Title:
The APM-North Catalogue
Short Name:
I/267
Date:
21 Oct 2021
Publisher:
CDS
Description:
****************************************************************** This version is a preliminary adaptation of the APM, covering the Northern sky at high galactic latitudes only. ****************************************************************** The catalogue APMCAT-POSS1-1.0 is derived from the first epoch (1949-1958) Palomar Observatory-National Geographic Sky Survey (POSS). The catalog is based on digitised scans with the laser based Cambridge Automated Plate Measurement(APM) machine of both the blue O plates and red E plates. The plates are scanned with a pixel sampling 8microns which corresponds 0.49 arcsecs at the nominal plate scale of 61arcsec/mm (16.4 micron/arcsec). Further details about the survey material can be found in Minkowski and Abell 1963 and Lund and Dixon 1973.
585. The CMT CCD Drift Scan Survey
ID:
ivo://CDS.VizieR/I/282
Title:
The CMT CCD Drift Scan Survey
Short Name:
I/282
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is CMC12 (Version 1.0), an astrometric and photometric catalogue of 6.3 million stars in the red magnitude range 9 to 17. The Carlsberg Meridian Telescope (CMT) underwent a major upgrade in March 1999. A 2k by 2k CCD camera was installed with a Sloan r' filter operating in a drift scan mode. With the new system, the magnitude limit is r'_CMT_=17 and the positional accuracy is about 0.035". The main task of the CMT is to map the sky in the declination range -3{deg} to +30{deg} with the aim of providing an astrometric, and photometric, catalogue that can accurately transfer the Hipparcos/Tycho reference frame to Schmidt plates. The current release (Version 1.0) comprises all the observations made between March 1999 and March 2002 with the new CCD in the declination band -3{deg} to +3{deg}. It is intended to release the rest of the catalogue later. A more complete description is available in the documentation at http://www.ast.cam.ac.uk/~dwe/SRF/cmc12/cmc12_documentation.ps or http://www.ast.cam.ac.uk/~dwe/SRF/cmc12/cmc12_documentation.pdf
586. The Core of NGC 6624
ID:
ivo://CDS.VizieR/J/AJ/109/639
Title:
The Core of NGC 6624
Short Name:
J/AJ/109/639
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the Faint Object Camera on the Hubble Space Telescope (HST) to observe three fields near the center of the post-collapse globular cluster NGC 6624 in B and V. We use individual stellar positions and a maximum-likelihood technique to measure a position for the cluster center. We then transfer this position and the position of the x-ray source 4U 1820-30 to right ascension and declination, and correct an error of 1.8" in an earlier paper. From star counts, we obtain a density profile, with a power-law cusp of slope -0.84 +/- 0.16. No flat core is evident. We construct color-magnitude diagrams down to the main-sequence turnoff near the cluster center, and more than three magnitudes below the turnoff in the outermost field at r=28". The former diagram reveals a central population of blue stragglers, which has not previously been observed in this cluster. These blue stragglers are quite similar in specific frequency to those recently observed by HST in the core of 47 Tuc, and their presence adds to the growing evidence of stellar interactions in dense globular-cluster cores.
587. The epoch ICRF
ID:
ivo://CDS.VizieR/J/MNRAS/430/2633
Title:
The epoch ICRF
Short Name:
J/MNRAS/430/2633
Date:
21 Oct 2021
Publisher:
CDS
Description:
The epoch International Celestial Reference Frame (epoch ICRF) is proposed as a new concept in order to consider the effect of apparent proper motion of the position of a radio source due to acceleration of the spatial origin of the ICRF, the centre of mass of the Solar system. This apparent proper motion has a magnitude of approximately 5.8-microarcsec ({mu}as) per year, and for the 30-year very long baseline interferometry (VLBI) observational history these position variations will exceed 100{mu}as. We show that the dipole structure of the apparent proper motions leads to global rotation in the ICRF2 and the main term, the shift of direction of the origin of right ascension, reaches 25{mu}as per century. The 'epoch ICRF' is constructed using epoch positions at J2000.0 and apparent proper motions of radio sources, which are reported here for 295 ICRF2-defining sources.
588. The extended Gaia-PS1-SDSS (GPS1+) proper motion catalog
ID:
ivo://CDS.VizieR/I/351
Title:
The extended Gaia-PS1-SDSS (GPS1+) proper motion catalog
Short Name:
I/351
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Gaia + PanSTARRS1 (PS1) + Sloan Digital Sky Survey (SDSS) + Two Micron All-Sky Survey (2MASS) (GPS1) catalog was released in 2017. It delivered precise proper motions for around 350 million sources down to a magnitude of r~20mag. In this study, we present GPS1+, the extension GPS1 catalog down to r~22.5mag, based on Gaia data release 2 (DR2), PS1, SDSS, and 2MASS astrometry. GPS1+ totally provides proper motions for ~400 million sources with a characteristic systematic error of less than 0.1mas/yr. This catalog is divided into two subsamples, i.e., the primary and secondary parts. The primary ~264 million sources have either or both Gaia and SDSS astrometry, with a typical precision of 2.0-5.0mas/yr. In this part, ~160 million sources have Gaia proper motions, and we provide another new proper motion for each of them by building a Bayesian model. Relative to Gaia's values, the precision is improved by ~0.1dex on average; ~50 million sources are the objects whose proper motions are missing in Gaia DR2, and we provide their proper motions with a precision of ~4.5mas/yr. The remaining ~54 million faint sources are beyond Gaia detecting capability, and we provide their proper motions for the first time with a precision of 7.0mas/yr. However, the secondary ~136 million sources only have PS1 astrometry, where the average precision is worse than 15.0mas/yr. The large uncertainty probably limits it to qualitative applications. All the proper motions have been validated using QSOs and the existing Gaia proper motions. The catalog will be available via the TAP Service in the German Astrophysical Virtual Observatory.
589. The Fifth Catalogue of Nearby Stars (CNS5)
ID:
ivo://org.gavo.dc/cns5/q/cone
Title:
The Fifth Catalogue of Nearby Stars (CNS5)
Short Name:
CNS5
Date:
27 Dec 2024 08:31:04
Publisher:
The GAVO DC team
Description:
The Fifth Catalogue of Nearby Stars (CNS5) aims to provide the most volume-complete sample of stars in the solar neighbourhood. The CNS5 is compiled based on trigonometric parallaxes from Gaia EDR3 and Hipparcos, and supplemented with astrometric data from Spitzer and ground-based surveys carried out in the infrared. The CNS5 catalogue is statistically complete down to 19.7 mag in G-band and 11.8 mag in W1-band absolute magnitudes, corresponding to a spectral type of L8. Continuous updates of observational data for nearby stars from all sources were collected and evaluated. For all known stars in the 25 pc sphere around the Sun, the best values of positions in space, velocities, and magnitudes in different filters are presented.
590. The fifth U.S. Naval Observatory CCD Astrograph Catalog (UCAC5)
ID:
ivo://org.gavo.dc/ucac5/q/cone
Title:
The fifth U.S. Naval Observatory CCD Astrograph Catalog (UCAC5)
Short Name:
UCAC 5
Date:
27 Dec 2024 08:31:04
Publisher:
The GAVO DC team
Description:
New astrometric reductions of the US Naval Observatory CCD Astrograph Catalog (UCAC) all-sky observations were performed from first principles using the TGAS stars in the 8 to 11 magnitude range as reference star catalog. Significant improvements in the astrometric solutions were obtained and the UCAC5 catalog of mean positions at a mean epoch near 2001 was generated. By combining UCAC5 with Gaia DR1 data new proper motions on the Gaia coordinate system for over 107 million stars were obtained with typical accuracies of 1 to 2 mas/yr (R = 11 to 15 mag), and about 5 mas/yr at 16th mag. Proper motions of most TGAS stars are improved over their Gaia data and the precision level of TGAS proper motions is extended to many millions more, fainter stars. The database table uses actual NULLs for missing photometry, and all angular coordinates have been homogenised to degrees.

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