The Impact of the GAIA Experiment on Eclipsing Binary Star Studies

• Main Author: Niarchos, P G
• Format: Conference Proceeding
• Language: English
• ISSN: 0094-243X
• DOI: 10.1063/1.2348001

GAIA, the approved cornerstone 6 ESA mission, will observe up to a billion stars in our Galaxy and obtain their astrometric positions on a micro-arcsec level, multi-band photometry as well as spectroscopic observations. The GAIA large-scale photometric survey will have significant intrinsic scientific value for the study of variable stars of nearly all types, including detached eclipsing binaries, near-contact or contact binaries and pulsating stars. It is expected that about 1 X 106 Eclipsing Binaries (EBs) (with V 16 mag) will be discovered and the observing fashion will be quite similar to Hipparcos/Tycho mission operational mode. On the other hand, GAIA's spectrograph will be able to secure useful radial velocities for binaries down to V 17 mag. The combined astrometric, photometric and spectroscopic data will be used to compute the physical parameters of the observed EBs. Even if for only 1% of the observed EBs reliable physical parameters could be derived, this would be a great contribution to stellar astrophysics and a giant leap in comparison with what has been obtained so far from ground-based observations. From a study of a small sample of EBs, it is shown that the agreement between the fundamental stellar parameters, derived from ground-based and Hipparcos (GAIA-like) observations, is more than satisfactory. The percentage difference between the absolute elements derived from GAIA-like observations and those from ground-based observations is of the order 2% or lower. These results are encouraging and demonstrate that GAIA data will be suitable to obtain accurate binary solutions.