Unveiling the abundance signature of M dwarf stars with planets

Planetary  systems  are  found  around   a  wide  variety  of  stellar
   hosts.  However,  our  understanding of  which  stellar  properties
   influence  planet   formation  is  still  largely   biased  towards
   main-sequence, solar-type  stars. While low-mass stars  (M dwarfs)
   have been recognised as promising  targets in the search for small,
   rocky  planets, detailed  chemical studies  of large  samples of  M
   dwarfs with planets are still missing. This is because the accurate
   determination of the stellar parameters  and abundances of M dwarfs
   is a  difficult task.  To overcome this  difficulty we  developed a
   methodology to determine stellar  abundances of elements other than
   iron for M  dwarf stars form high-resolution,  optical spectra. Our
   methodology is based on the use of principal component analysis and
   sparse Bayesian's method. We made use of a set of M dwarfs orbiting
   around  an  FGK   primary  with  known  abundances   to  train  our
   methods.  In this  contribution we  applied our  methods to  derive
   stellar metallicities and abundances of  a large sample of M dwarfs
   observed   within  the   framework  of   current  radial   velocity
   surveys.   We  discuss   whether  the   correlations  between   the
   metallicity, individual  chemical abundances, and mass  of the star
   and the presence  of different type of planets found  for FGK stars
   still holds for the less massive  M dwarf stars and set the results
   into the context of current planet formation models.