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.
The first U.S. Naval Observatory Astrometric Robotic Telescope Catalog
URAT1 star catalog
Short Name:
urat1.main
Date:
27 Dec 2024 08:31:00
Publisher:
The GAVO DC team
Description:
URAT1 is an observational catalog at a mean epoch between 2012.3 and
2014.6; ot covers the magnitude range 3 to 18.5 in R-band, with a
positional precision of 5 to 40 mas. It covers most of the northern
hemisphere and some areas down to -24.8° in declination.
In the GAVO data center, we left out all columns originating from
cross matches with other catalogs; on-the fly crossmatches can be done
in our TAP service.
The fourth U.S. Naval Observatory CCD Astrograph Catalog (UCAC4)
Short Name:
ucac4 scs
Date:
27 Dec 2024 08:31:12
Publisher:
The GAVO DC team
Description:
UCAC4 is a compiled, all-sky star catalog covering mainly the 8 to 16
magnitude range in a single bandpass between V and R.
Positional errors are about 15 to 20 mas for stars in the 10 to 14 mag
range. Proper motions have been derived for most of the about 113
million stars utilizing about 140 other star catalogs with significant
epoch difference to the UCAC CCD observations. These data are
supplemented by 2MASS photometric data for about 110 million stars and
5-band (B,V,g,r,i) photometry from the APASS (AAVSO Photometric
All-Sky Survey) for over 50 million stars. UCAC4 also contains error
estimates and various flags. All bright stars not observed with
the astrograph have been added to UCAC4 from a set of Hipparcos and
Tycho-2 stars. Thus UCAC4 should be complete from the brightest stars
to about R=16, with the source of data indicated in flags.
This is a clean and well characterised catalogue of objects within 100pc of
the Sun from the Gaia early third data release. We characterise the
catalogue using the full data release, and comparisons to other catalogues
in literature and simulations. For all candidates (measured parallax <
8 mas), we calculate a distance probability function using Bayesian
procedures and mock catalogues for the prediction of the priors. For each
entry using a random forest classifier we attempt to remove sources with
spurious astrometric solutions.
This results in 331312 objects that should contain at least 92% of stars
within 100 pc at spectral type M9.
GCNS comes with several auxiliary tables, in particular lists of
resolved stellar systems, of known neary stars not found in eDR3 and
of candidates of Hyades and ComaBer cluster members.
This is a clean and well characterised catalogue of objects within 100pc of
the Sun from the Gaia early third data release. We characterise the
catalogue using the full data release, and comparisons to other catalogues
in literature and simulations. For all candidates (measured parallax <
8 mas), we calculate a distance probability function using Bayesian
procedures and mock catalogues for the prediction of the priors. For each
entry using a random forest classifier we attempt to remove sources with
spurious astrometric solutions.
This results in 331312 objects that should contain at least 92% of stars
within 100 pc at spectral type M9.
GCNS comes with several auxiliary tables, in particular lists of
resolved stellar systems, of known neary stars not found in eDR3 and
of candidates of Hyades and ComaBer cluster members.
This catalog combines Gaia DR1, Pan-STARRS 1, SDSS and 2MASS astrometry
to compute proper motions for 350 million sources across three-fourths of
the sky down to a magnitude of mr≈20. Positions of galaxies from Pan-STARRS 1
are used to build a reference frame for PS1, SDSS, and 2MASS data.
Gaia DR1 is adapted to that reference frame by exploiting that locally,
proper motions are linear.
GPS1 has a characteristic systematic error of less than 0.3 mas/yr, and
a typical precision of 1.5−2.0 mas/yr. The proper motions have been
validated using galaxies, open clusters, distant giant stars and QSOs. In
comparison with other published faint proper motion catalogs, GPS1's
systematic error (<0.3 mas/yr) is about 10 times better than that of PPMXL
and UCAC4 (>2.0 mas/yr). Similarly, its precision (~1.5 mas/yr) is
an improvement by ∼ 4 times relative to PPMXL and UCAC4 (∼6.0 mas/yr).
For QSOs, the precision of GPS1 is found to be worse (∼2.0−3.0 mas/yr),
possibly due to their particular differential chromatic refraction (DCR).
GAVO's ADQL reference card briefly gives an overview of the SQL
dialect used in the VO. It is available as a PDFfile and as Scribus
source under the CC-BY license.
The GAVO puzzlers are little training problems solvable by standard
VO techniques (data discovery, SIAP, Cone Search, TAP). They assume
some familiarity with common astronomical concepts (they were
originally given out during meetings of the German Astronomische
Gesellschaft) but are designed to be solvable using common, standard
tools and in reasonable time. Solutions are also given.
The Global TAP schema is an attempt at a simple way to present a
union of all TAP_SCHEMA instances globally, where right now GloTS only
contains tables and columns. It is primarily intended as a quick (and
relatively dirty) way for data collection discovery until other means
are ready.
![To the extent possible under law, the publisher has waived all copyright and related or neighboring rights to GAVO's ADQL course. For details, see the `Creative Commons CC0 1.0 Public Domain dedication <http://creativecommons.org/publicdomain/zero/1.0/>`_. Of course, you should still give proper credit when using this data as required by good scientific practice. .. image:: /static/img/cc0.png :alt: [CC0]](/registry-search/?f%5Bpublisher_facet_trim%5D%5B%5D=The+GAVO+DC+team&f%5Brights_facet%5D%5B%5D=To+the+extent+possible+under+law%2C+the+publisher+has+waived+all+copyright+and+related+or+neighboring+rights+to+GAVO%27s+ADQL+course.++For+details%2C+see+the+%60Creative+Commons+CC0+1.0+Public+Domain+dedication+%3Chttp%3A%2F%2Fcreativecommons.org%2Fpublicdomain%2Fzero%2F1.0%2F%3E%60_.++Of+course%2C+you+should+still+give+proper+credit+when+using+this+data+as+required+by+good+scientific+practice.%0A%0A..+image%3A%3A+%2Fstatic%2Fimg%2Fcc0.png%0A+++%3Aalt%3A+%5BCC0%5D%0A%0A&f%5BvalidationLevel_facet%5D%5B%5D=2){kind=link}