Spectral photometry and quantitative analysis of the helium star HD 168785.
Abstract
Summary. A detailed spectral analysis of the helium rich star HD 168785 yields the following parameters: effective temperature, Teff =24000 + 1000 0K; gravity, logg =3.310.15; hydrogen and helium abundances by number fraction, =0.55 and =0.45, respectively; microturbulent velocity, Vt = 5.01 2 km/s. Metals, especially oxygen, appear to be underabundant. From the proper motion data, the star should be not more than 1 kpc away. This, together with the atmospheric param eters yield the star's mass, m, radius, R, and luminosity L:m/m0 = 1.0, R/R0 =3.4, L/L0 -4 x 10 . Like HD 144941, HD 168785 seems to be another example of an evolved low mass star with moderate helium enrichment. - Key words: stellar atmospheres helium stars abundances evolution
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 1974
- Bibcode:
- 1974A&A....36..201K