Mass loss in HR 1040 (A0 Ia): Analysis of Mg II lambda2802 and H. cap alpha

Journal Article · Tue Mar 15 04:00:00 EST 1983 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160820· OSTI ID:5940968

Kunasz, P B; Morrison, N D; Spressart, B

Recent observations of H..cap alpha.. in the A0 type supergiant HR 1040 (HD 21389) are presented, and a profile of one of the Mg II resonance lines, obtained with the International Ultraviolet Explorer, is compared with a previous observation. No significant variation is found despite the fact that the Mg II line profiles in this star, which are violet shifted by 160 km s/sup -1/, are unsaturated and rather sensitive to the density of the wind. Models similar to those developed for ..cap alpha.. Cygni by Kunasz and Praderie are adapted to HR 1040, and computed profiles for Mg II lambda2802 are compared with those observed. For models in which Mg/sup +/ dominates the magnesium ionization balance, Mroughly-equal10/sup -9.5/ M/sub sun/ yr/sup -1/. A progression of successful models is also presented in which Mg/sup +/ is increasingly photoionized to Mg/sup + +/ as the assumed value of the ultraviolet radiation temperature is raised, while the mass-loss rate is increased in such a way as to maintain the column density of Mg/sup +/ in the wind roughly constant.

• OSTI ID: 5940968
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 266:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BALMER LINES
CHARGED PARTICLES
GIANT STARS
IONS
MAGNESIUM IONS
MATHEMATICAL MODELS
NUMERICAL SOLUTION
SPECTRA
STAR MODELS
STARS
STELLAR WINDS
SUPERGIANT STARS
ULTRAVIOLET SPECTRA