A Spatially Dependent Correction of Gaia EDR3 Parallax Zero-point Offset based on 0.3 million LAMOST DR8 Giant Stars
Abstract
We have studied the zero-point offset of Gaia Early Data Release 3 (EDR3) parallaxes based on a sample of 0.3 million giant stars built from the LAMOST data with distance accuracy better than 8.5%. The official parallax zero-point corrections largely reduce the global offset in the Gaia EDR3 parallaxes: the global parallax offsets are -27.9 μas and -26.5 μas (before correction) and +2.6 μas and +2.9 μas (after correction) for the five- and six-parameter solutions, respectively. The bias of the raw parallax measurements is significantly dependent on the G magnitudes, spectral colors, and positions of stars. The official parallax zero-point corrections could reduce parallax bias patterns with G magnitudes, while could not fully account the patterns in the spaces of the spectral colors and positions. In the current paper, a spatially dependent parallax zero-point correction model for Gaia EDR3 five-parameter solution in the LAMOST footprint is first provided with the advantage of huge number of stars in our sample.
- Publication:
-
The Astronomical Journal
- Pub Date:
- April 2022
- DOI:
- 10.3847/1538-3881/ac4dec
- arXiv:
- arXiv:2201.09438
- Bibcode:
- 2022AJ....163..149W
- Keywords:
-
- Stellar parallax;
- Stellar distance;
- Parallax;
- 1618;
- 1595;
- 1197;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 9 pages, 6 figures, 1 table, accepted for publication in AJ