An Investigation of the Physical Basis of Luminosity Classification in A, F and G-type Stars

Session 58 - Stellar Modelling/Abundances.
Display session, Wednesday, June 12
Great Hall,

[58.01] An Investigation of the Physical Basis of Luminosity Classification in A, F and G-type Stars

R. O. Gray (Appalachian State Univ.), J. S. Arlt (Appalachian State Univ. and REU Student)

We present preliminary results from an ongoing project to investigate the physical basis of luminosity classification on the MK spectral classification system for the late A, F and G-type stars. Earlier invesigations (Bolton 1971, Gustafsson and Gray 1988, Gray and Garrison 1989) have indicated the importance of microturbulence in the behavior of luminosity classification criteria (based on lines of ionized metals) used in late A, F and G-type stars. We describe a project that uses spectral synthesis to analyze MK-resolution (1.8 ÅCCD spectra obtained with the 0.8m telescope of the Dark Sky Observatory (Appalachian State University). We discuss preliminary results detailing how the effects of microturbulence, abundances and gravity can be separated for a given star using MK-resolution spectra.

Program listing for Wednesday