The frequency by mass of Galactic carbon stars inferred from Gaia
  measurements of star cluster members
  We investigate the frequency of occurrence of Galactic carbon stars as a
function of progenitor mass using Gaia data. Small number statistics limit
fidelity, but C star frequency agrees with that observed in the Magellanic
Clouds (MCs) down to $m \approx1.67$ M$_\odot$. At $m \approx 1.38$ M$_\odot$,
the frequency rises by a factor of three even though the frequency appears to
drop to zero for the MCs. In fact this is due to a lack of clusters at the key
age range in the MCs. At $m \approx 1.24$ M$_\odot$ and below, no C stars are
observed, corresponding to ages older than 4 Gyr. Within uncertainties, C~star
frequency in M 31 is consistent with that of the Galaxy and the MCs. We find an
ambiguous C-star candidate at $\sim$7 M$_\odot$.
