The Possibility of GRB Investigations by ESA Satellite Gaia

Abstract

We refer on further studies on possibility to investigate the Optical Afterglows and Optical Transients of GRBs by the ESA satellite Gaia to be launched in 2012, The satellite will focus on highly precise astrometry of stars and all objects down to limiting magnitude 20. Albeit focusing on astrometry related matters, the satellite will also provide photometric and spectral information and hence important inputs for various branches of astrophysics. Within the Gaia Variability Unit CU7 and related work package Specific Object Studies there has been a sub–work package accepted for optical counterparts to celestial high‐energy sources, a category which includes the optical counterparts (i.e. optical transients and optical afterglows, including counterparts of XRFs and yet hypothetical orphan afterglows) of GRBs. Although the sampling of photometric data will not be optimal for this type of work, the strength of Gaia in such analyses is the fine spectral resolution (spectro–photometry) which will allow the correct classification of related triggers. The possibilities to detect and to analyze optical transients and optical afterglows of GRBs by Gaia will be presented and discussed.