The origin of carbon
Carbon was not among the elements analysed in our large disk-star project.
It is an abundant element in the Galaxy, and apart from its chemical
and biological significance it is important for stellar
opacities and energy generation, and knowledge about its abundance is
significant for estimates of stellar ages.
We later detected that a forbidden [C I] line is present in the
spectra originally obtained for the stars in the large disk-star project.
The line is very weak, but
Andersson & Edvardsson (1994, A&A 290, 590), give the results
of a first attempt to utilize the line for abundance studies.
Now, much higher-S/N observations of 80 stars have been analysed:
Gustafsson et al. (1999, A&A 342, 426).
The new results and comparisons with abundances found in irregular galaxies
show nicely that the carbon existing in the Galaxy and elsewhere in the
Universe is mainly being produced in massive stars,
and rules out e.g. carbon stars as a dominating carbon producer.
Latest update: June 2, 2000