The Atmospheres of the F-Type Supergiants I. Calibration of the Luminosity-Sensitive O i Lambda 7774 Line
Abstract
The equivalent width of the 0 1 7774 line has been measured with a narrow-band photoelectric technique in 59 stars of spectral types A() G3 and luminosity classes Ia-V. By calibrating the line strength in 10 F-type supergiants of known luminosities, we find that it indicates their absolute magnitudes with an accuracy of 0.5 mag in the range -4> M > -9, a significant improvement over previous methods. The calibration permits some of the most luminous stars known to be used as distance indicators.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- March 1972
- DOI:
- 10.1086/190254
- Bibcode:
- 1972ApJS...24..247O