The origin of dwarf carbon stars

The origin of dwarf carbon stars is a mystery nearly 40 years old. These
stars are similar in mass and temperature to the Sun, but are dominated
by carbon instead of oxygen. While researchers have hypothesised that
such a carbon-rich star can give birth to carbon dominated planetary
systems, the working hypothesis is that these stars are the product of
binary star evolution. Remarkably, a significant number of dwarf carbon
stars appear to belong to the ancient halo population, and thus hold
clues to the earliest stages of star formation and Galactic chemical
evolution. The observational project will analyse radial velocity and
related data to characterise any binary systems for the first time
(fraction, periods, mass transfer). Another aspect might be
construction of the first spectral sequence of these stars using
available data and models. Kinematical information can also be used to
establish age and membership in the Galactic halo and disk.