Evolved stars in the Local Group galaxies - III. AGB and RSG stars in
  Sextans A
  We study the evolved stellar population of the galaxy Sextans A. This galaxy
is one of the lowest metallicity dwarfs in which variable asymptotic giant
branch stars have been detected, suggesting that little metal enrichment took
place during the past history. The analysis consists in the characterization of
a sample of evolved stars, based on evolutionary tracks of asymptotic giant
branch and red super giant stars, which include the description of dust
formation in their winds. Use of mid-infrared and near-infrared data allowed us
to identify carbon-rich sources, stars undergoing hot bottom burning and red
super giants. The dust production rate, estimated as $6\times 10^{-7}
M_{\odot}/$yr, is dominated by $\sim 10$ carbon stars, with a small
contribution of higher mass M-stars, of the order of $4\times 10^{-8}
M_{\odot}/$yr. The importance of this study to understand how dust production
works in metal-poor environments is also evaluated.
