Astronomy and Astrophysics – Astrophysics
Scientific paper
May 1983
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1983apj...268..225s&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 268, May 1, 1983, p. 225-227.
Astronomy and Astrophysics
Astrophysics
43
Binary Stars, Chemical Composition, Stellar Envelopes, Stellar Evolution, Helium, Hydrogen, Stellar Mass, Stellar Structure
Scientific paper
An explanation for the nature and evolution of the extremely hydrogen deficient binary Upsilon Sagittarii which is consistent with all observational and theoretical facts. First, the system goes through a Case B mass exchange in which most of the hydrogen rich envelope of a massive primary (5 to 14 solar masses) is lost. The remaining envelope still contains about 50 percent hydrogen (by number), but is now of negligible mass, so that the star evolves like a pure helium star. If its mass is between 1 and 2 solar masses the star reaches low surface temperatures and becomes a supergiant before the onset of carbon burning. This star (the original primary) then fills its Roche lobe a second time,spilling its now helium rich envelope over onto the secondary (Case BB mass exchange). It is argued that Upsilon Sagittarii is in this state at the present time, and that the visible star is an evolved helium star of about 1 solar mass with a degenerate carbon-oxygen core and a helium burning shell which provides the high luminosity. Previously announced in Star as N26117
Drilling John S.
Schoenberner Detlef
No associations
LandOfFree
On the nature of Upsilon Sagittarii does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On the nature of Upsilon Sagittarii, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the nature of Upsilon Sagittarii will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1585454