Some Observational Implications of Extended Static O-Star Model Atmospheres
Abstract
Some results and observational implications are presented for the first extended spherical non-LTE model atmospheres in hydrostatic and radiative equilibrium. These models all correspond to a star with = 60 , L = 1.25 X 106 Lo and R = 24 , with an effective temperature Te 39,500 K and surface gravity log g 3.45 (spectral type near 06). They are differentiated by the magnitude and radial dependence of a radiation-force multiplier , inserted into the equation of hydrostatic equilibrium, to simulate the effect of radiation force on opacity sources (e.g., lines) that have not been included in the calculations. It has been possible to obtain models very close to the limit at which the radiation force balances the gravity. Hydrogen and helium (`7= 0.1) constitute the gas; siz hydrogen lines are treated explicitly. These models show La in emission, the lower Balmer lines in absorption, the Balmer jump in absorption, and both infrared and ultraviolet excesses relative to the visual. Continuum jumps and gradients, -system colors, and equlvalent widths of Ha, Hp, and H are tabulated and discussed briefly. Subject headings: atmospheres, stellar - radiative transfer
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1974
- DOI:
- 10.1086/181459
- Bibcode:
- 1974ApJ...189L..39M