A Spectroscopic Estimate of the Atmospheric Properties of O and B Stars.
Abstract
Equivalent widths of lines in the spectra of six 0 stars were measured using the coude' scanner of the 100-inch telescope. These data and those in the literature for r Sco are fitted to theoretical line-strength calculations in an attempt to derive the effective temperatures, gravities, and helium abundances of these stars. It is found that the effective temperatures and gravities are well determined, while the helium abundance can be estimated only with fair accuracy; it appears that the best estimate for N(He) /N(H) is about 0 15 or 0.2. Comparisons are made between the computed and observed profiles for X 4686 in Sco and 10 Lac; a good fit with the 10 Lac observations can be obtained only with a turbulent velocity of the order of 20 km/sec.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1964
- DOI:
- 10.1086/147993
- Bibcode:
- 1964ApJ...140..885M