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431. Second Greenwich Catalog of Stars for 1925.0
ID:
ivo://CDS.VizieR/I/34
Title:
Second Greenwich Catalog of Stars for 1925.0
Short Name:
I/34
Date:
21 Oct 2021
Publisher:
CDS
Description:
The observations for these two catalogs were made with the transit circle at the Royal Observatory in Greenwich, England, between the years 1922 and 1930 under the direction of Sir Frank Dyson, Astronomer Royal. Part I contains fundamental stars contained in the annual volumes of Greenwich Observations of the Sun, Moon and Planets. In addition, 232 stars observed at the prime vertical, South of +32dDec., have been observed. Part II contains all stars down to 7.9 mag in the A.G. scale between the limits of 32d and 64d Dec with the addition of 285 fainter stars in the sparse region of the sky from 12h to 16h RA. From internal information, the probable error of one observation of a star is found to be +/-0.35 arcsec in RA and +/-0.28 arcsec in DE. As the number of observations is generally 5, the pe of a position in the catalog, apart from systematic errors, should be +/-0.15 arcsec. In determining the proper motion of the fundamental stars, the positions of this catalogue were combined with the First Greenwich Catalog of Stars for 1925.0 (Observed 1915-1921), the two Pulkova Catalogues and the two Cape Catalogues preceding this catalogue. Note that the problable errors on the proper motions are not included in this electronic version.
432. Second VLBA calibrator survey: VCS2
ID:
ivo://CDS.VizieR/J/AJ/126/2562
Title:
Second VLBA calibrator survey: VCS2
Short Name:
J/AJ/126/2562
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents an extension of the Very Long Baseline Array Calibrator Survey, called VCS2, containing 276 sources. This survey fills in regions of the sky that were not completely covered by the previous VCS1 calibrator survey. The VCS2 survey includes calibrator sources near the Galactic plane, -30{deg}<DE<-45{deg}, and VLA calibrators. The positions have been derived from astrometric analysis of the group delays measured at 2.3 and 8.4 GHz using the Goddard Space Flight Center CALC/SOLVE package. From the VLBA snapshot observations, images of the calibrators are available, and each source is given a quality code for anticipated use. The VCS2 catalog is available from the NRAO Web site.
433. Short- and long-term pm of close dwarfs
ID:
ivo://CDS.VizieR/J/PAZh/41/896
Title:
Short- and long-term pm of close dwarfs
Short Name:
J/PAZh/41/896
Date:
21 Oct 2021
Publisher:
CDS
Description:
Motions of 1308 stars with large proper motions ({mu}>300mas/yr) up to 17 mag were investigated using the results of observations conducted with Pulkovo Normal Astrograph and images taken from data bases of sky surveys (DSS, SDSS DR12, WISE). Basic idea of search of double stars with this material is a comparison between long-term proper motion (POSS2-POSS1, epoch difference is about 50yr) and short-term proper motion (2MASS, SDSS, WISE, Pulkovo, epoch difference is about 10yr). Star is classified as delta-mu-binary candidate in the case of statistically significant difference of short-term and long-term proper motions. This condition is realised for 121 stars of our target list. Additional evidence of duplicity was obtained with comparison of our proper motions with data of several parallax determination programs. Analysis of accurate SDSS photometric values of our stars allows us to conclude that four stars (J0656+3827, J0838+3940, J1229+5332, J2330+4639) are probably binary systems which consist of wite dwarf + M-dwarf.
434. Significance of VLBI/Gaia position offsets
ID:
ivo://CDS.VizieR/J/MNRAS/467/L71
Title:
Significance of VLBI/Gaia position offsets
Short Name:
J/MNRAS/467/L71
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have cross matched the Gaia Data Release 1 secondary data set that contains positions of 1.14 billion objects against the most complete to date catalogue of very long baseline interferometry (VLBI) positions of 11.4 thousand sources, almost exclusively active galactic nuclei. We found 6064 matches, i.e. 53 per cent radio objects. The median uncertainty of VLBI positions is a factor of 4 smaller than the median uncertainties of their optical counterparts. Our analysis shows that the distribution of normalized arc lengths significantly deviates from Rayleigh shape with an excess of objects with small normalized arc lengths and with a number of outliers. We found that 6 per cent matches have radio-optical offsets significant at 99 per cent confidence level. Therefore, we conclude there exists a population of objects with genuine offsets between centroids of radio and optical emission.
435. Sixth Catalogue of Fundamental Stars (FK6)
ID:
ivo://CDS.VizieR/I/264
Title:
Sixth Catalogue of Fundamental Stars (FK6)
Short Name:
I/264
Date:
21 Oct 2021
Publisher:
CDS
Description:
The FK6 is a suitable combination of the results of the HIPPARCOS (Cat. <I/239>) astrometry satellite with ground-based data, measured over more than two centuries. The FK6 gives other solutions than the classical `single-star mode' (SI mode), which take into account the fact that hidden astrometric binaries among `apparently single-stars' introduce sizable `cosmic errors' into the quasi-instantaneously measured HIPPARCOS proper motions and positions. The FK6 gives in addition to the SI mode the `long-term prediction (LTP) mode' and the `short-term prediction (STP) mode'. These LTP and STP modes are on average the most precise solutions for apparently single stars, depending on the epoch difference with respect to the HIPPARCOS epoch of about 1991. The FK6(I) results from the combination of FK5(I) (Cat. <I/149>) with Hipparcos results. Among its 878 stars, it contains 340 objects classified as `astrometrically excellent stars', most suited for high-precision astrometry. The typical mean error of an FK6(I) proper motion is 0.35 mas/year in the single-star mode (about two times better than Hipparcos), and 0.50 mas/year in the long-term prediction mode (about four times better than Hipparcos). The FK6(III) results from the combination of stars from FK5 extension (Cat. <I/175>) with Hipparcos. Among its 3272 stars, it contains 1928 objects classified as `astrometrically excellent stars'. The typical mean error of an FK6(III) proper motion is 0.59 mas/year in the single-star mode, and 0.93 mas/year in the long-term prediction mode.
436. SKY2000 Catalog, Version 3
ID:
ivo://CDS.VizieR/V/105
Title:
SKY2000 Catalog, Version 3
Short Name:
V/105
Date:
21 Oct 2021
Publisher:
CDS
Description:
The SKYMAP Star Catalog System consists of a Master Catalog stellar database and a collection of utility software designed to create and maintain the database and to generate derivative mission star catalogs (run catalogs). It contains an extensive compilation of information on almost 300000 stars brighter than 8.0 mag. The original SKYMAP Master Catalog was generated in the early 1970's. Incremental updates and corrections were made over the following years but the first complete revision of the source data occurred with Version 4.0. This revision also produced a unique, consolidated source of astrometric information which can be used by the astronomical community. The derived quantities were removed and wideband and photometric data in the R (red) and I (infrared) systems were added. Version 3 of the SKY2000 Master Catalog was completed in May of 2000 and represents an incremental but substantial improvement over Version 2 (Cat. <V/102>). A global replacement of photovisual (ptv) and photographic (ptg) magnitudes and of Henry Draper spectral types was performed using as sources the SAO Catalog, the PPM catalogs, and the HD catalogs. Several hundred entries previously lacking them now have CCD ST magnitudes from the star tracker onboard the SWAS spacecraft (transformed to the photometric system defined by the RXTE CCD ST data in SKY2000 Version 2). Several thousand missing HD catalog identifiers (mostly for HD Extension stars) were added, and several hundred missing variable star identifiers were added. 61 stars bright enough for inclusion in SKY2000 were added, bringing the total number of entries in the SKY2000 Version 3 Master Catalog to 299,160 (299,161 in Rev. 1).
437. SKY2000 Catalog, Version 4
ID:
ivo://CDS.VizieR/V/109
Title:
SKY2000 Catalog, Version 4
Short Name:
V/109
Date:
21 Oct 2021
Publisher:
CDS
Description:
The SKYMAP Star Catalog System consists of a Master Catalog stellar database and a collection of utility software designed to create and maintain the database and to generate derivative mission star catalogs (run catalogs). It contains an extensive compilation of information on almost 300000 stars brighter than 8.0 mag. The original SKYMAP Master Catalog was generated in the early 1970's. Incremental updates and corrections were made over the following years but the first complete revision of the source data occurred with Version 4.0. This revision also produced a unique, consolidated source of astrometric information which can be used by the astronomical community. The derived quantities were removed and wideband and photometric data in the R (red) and I (infrared) systems were added. Version 4 of the SKY2000 Master Catalog was completed in April 2002; it marks the global replacement of the variability identifier and variability data fields. More details can be found in the description file sky2kv4.pdf. This version supersedes the previous versions 1(V/95), 2(V/102), and 3(V/105).
438. SKY2000 Master Catalog, Version 5
ID:
ivo://CDS.VizieR/V/145
Title:
SKY2000 Master Catalog, Version 5
Short Name:
V/145
Date:
21 Oct 2021
Publisher:
CDS
Description:
The SKYMAP Star Catalog System consists of a Master Catalog stellar database and a collection of utility software designed to create and maintain the database and to generate derivative mission star catalogs (run catalogs). It contains an extensive compilation of information on almost 300000 stars brighter than 8.0mag. The original SKYMAP Master Catalog was generated in the early 1970's. Incremental updates and corrections were made over the following years but the first complete revision of the source data occurred with Version 4.0. This revision also produced a unique, consolidated source of astrometric information which can be used by the astronomical community. The derived quantities were removed and wideband and photometric data in the R (red) and I (infrared) systems were added. Version 4 of the SKY2000 Master Catalog was completed in April 2002; it marks the global replacement of the variability identifier and variability data fields. More details can be found in the description file sky2kv4.pdf. The SKY2000 Version 5 Revision 4 Master Catalog differs from Revision 3 in that MK and HD spectral types have been added from the Catalogue of Stellar Spectral Classifications (B. A. Skiff of Lowell Observatory, 2005), which has been assigned source code 50 in this process. 9622 entries now have MK types from this source, while 3976 entries have HD types from this source. SKY2000 V5 R4 also differs globally from preceding MC versions in that the Galactic coordinate computations performed by UPDATE have been increased in accuracy, so that differences from the same quantities from other sources are now typically in the last decimal places carried in the MC. This version supersedes the previous versions 1(V/95), 2(V/102), 3(V/105) and 4(V/109).
439. SKY2000 - Master Star Catalog
ID:
ivo://CDS.VizieR/V/95
Title:
SKY2000 - Master Star Catalog
Short Name:
V/95
Date:
21 Oct 2021
Publisher:
CDS
Description:
The SKYMAP Star Catalog System consists of a Master Catalog stellar database and a collection of utility software designed to create and maintain the database and to generate derivative mission star catalogs (run catalogs). It contains an extensive compilation of information on almost 300000 stars.
440. SKY2000 - Master Star Catalog, Version 2
ID:
ivo://CDS.VizieR/V/102
Title:
SKY2000 - Master Star Catalog, Version 2
Short Name:
V/102
Date:
21 Oct 2021
Publisher:
CDS
Description:
The SKYMAP Star Catalog System consists of a Master Catalog stellar database and a collection of utility software designed to create and maintain the database and to generate derivative mission star catalogs (run catalogs). It contains an extensive compilation of information on almost 300000 stars brighter than 8.0 mag.

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