White Dwarfs as Seen by Gaia

International audienceThe launch of the Gaia satellite of ESA is approaching (scheduled in 2013) and the scientific community is preparing for the maximal scientific return. As white dwarfs (WDs) are very faint, (especially in the cool domain, T eff < 5 000K) they have been very hard to detect and only the closest ones have been observed until now. Gaia, through its 5-6 years survey of the whole sky down to magnitude 20-25 (depending on the colour of the source), will detect many faint WDs and most importantly, provide parallaxes for them. We provide a new characterisation of Gaia photometry for the case of WDs, deriving Gaia magnitudes and colours for WDs. Some transformations between some of the most common photometric systems and Gaia passbands are also derived to allow predictions of how WDs will be seen by Gaia