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Start Over Subject proper-motions Publisher The GAVO DC team Content Level Research
1. Adding catalog data to object lists using the VO
ID:
ivo://edu.gavo.org/hd/gavo_addpms
Title:
Adding catalog data to object lists using the VO
Date:
27 Dec 2024 08:31:06
Publisher:
The GAVO DC team
Description:
This brief tutorial shows you how to quickly add proper motions and photometry from Gaia to (almost) any object list using the Virtual Observatory. The VO protocol most suited to this kind of this is TAP ("table access protocol") and lets you transfer data and queries to database servers. In the example, we will be using TOPCAT as a client. There is no lock-in to it: There are libraries and other tools allowing an integration of TAP operations into arbitrary workflows – that's what standards are about. Tutorial supplements apply the techniques to Simbad, show how to use TAP from Python, and introduce UCDs.
2. The Gaia-PS1-SDSS (GPS1) Proper Motion Catalog
ID:
ivo://org.gavo.dc/gps1/q/cone
Title:
The Gaia-PS1-SDSS (GPS1) Proper Motion Catalog
Short Name:
GPS1
Date:
27 Dec 2024 08:31:00
Publisher:
The GAVO DC team
Description:
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).
3. The HSOY Catalog
ID:
ivo://org.gavo.dc/hsoy/q/q
Title:
The HSOY Catalog
Short Name:
HSOY SCS
Date:
27 Dec 2024 08:31:06
Publisher:
The GAVO DC team
Description:
HSOY is a catalog of 583'001'653 objects with precise astrometry based on PPMXL and Gaia DR1. Typical formal errors at mean epoch in proper motion are below 1 mas/yr for objects brighter than 10 mag, and about 5 mas/yr at the faint end (about 20 mag). South of -30 degrees, astrometry is significantly worse. HSOY also contains, where available, USNO-B, Gaia, and 2MASS photometry. HSOY's positions and proper motions are given for epoch J2000. The catalog becomes severely incomplete faintwards of 16 mag in the G-band. The mean epochs are typically very close to Gaia's J2015. HSOY still contains about 0.7% spurious close "binaries" (non-matched stars) from the original USNO-B (marked with non-NULL clone). Also, failed matches within Gaia DR1 contribute another 1.5% spurious pairs (marked with non-NULL comp). In both cases, astrometry presumably is sub-standard. More information is available at http://dc.g-vo.org/hsoy.