Evidence for a Systematic Offset of -80 μas in the Gaia DR2 Parallaxes
Abstract
We reprise the analysis of Stassun & Torres, comparing the parallaxes of the eclipsing binaries reported in that paper to the parallaxes newly reported in the Gaia second data release (DR2). We find evidence for a systematic offset of -82 ± 33 μas, in the sense of the Gaia parallaxes being too small, for brightnesses (G ≲ 12) and for distances (0.03-3 kpc) in the ranges spanned by the eclipsing binary sample. The offset does not appear to depend strongly on distance within this range, though there is marginal evidence that the offset increases (becomes slightly more negative) for distances ≳1 kpc, up to the 3 kpc distances probed by the test sample. The offset reported here is consistent with the expectation that global systematics in the Gaia DR2 parallaxes are below 100 μas.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2018
- DOI:
- 10.3847/1538-4357/aacafc
- arXiv:
- arXiv:1805.03526
- Bibcode:
- 2018ApJ...862...61S
- Keywords:
-
- binaries: eclipsing;
- parallaxes;
- stars: distances;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 6 pages, 2 figures, to appear in the Astrophysical Journal