SPEAKER: Bárbara Rojas-Ayala (IA-CAUP)
ABSTRACT: The intrinsically faint M dwarfs are the most numerous stars in the Galaxy, have main-sequence lifetimes longer than the Hubble time, and host some of the most interesting planetary systems known to date. Their identification and classification throughout the Galaxy is crucial to unraveling the processes involved in the formation of planets, stars and the Milky Way. The ESO Public Survey VISTA Variables in the Vía Láctea is a deep near-IR survey mapping the Galactic bulge and southern plane. The VVV b201 tile, located in the border of the bulge, was specifically selected for the characterisation of M dwarfs.In this talk, I will introduce the VVV survey and explain the empirical methods developed to selected M dwarf candidates from VISTA photometry, and to assign spectral types and expected distances for 23,345 objects in VVV b201. In the range 12<Ks<16, we identified 753 stars as possible giant contaminants out of 9,232 M dwarf candidates from a new NIR reduced proper motion diagram and colour cuts. Considering only 25 out of the first 26 epochs of VVV, we found transit-like signals in the light curves of 95 M dwarf candidates and of 12 possible giants. Thanks to its deeper photometry (about 4 magnitudes deeper than 2MASS), the VVV survey will be a major contributor to the discovery and study of M dwarfs and possible companions towards the center of the Milky Way.