BM orionis: The enigmatic eclipsing binary in the trapezium

Journal Article · Thu Apr 15 04:00:00 EST 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154299· OSTI ID:7361371

Popper, D M; Plavec, M

The enigma of BM Ori: namely, the apparent absence of spectral lines of a cooler component in spite of the considerable duration of approximately constant light during primary eclipse: is partially resolved. Weak lines of a secondary star of late A-type are found, and the orbits of both components are obtained. The primary component is a normal B3 star of mass 6 M/sub sun/, lying on the zero-age main sequence of the Orion Nebula cluster. The secondary, of mass 1.8 M/sub sun/, conforms in its axial ratio and moderate rotational velocity to models in pre--main-sequence differential rotation (Bodenheimer-Ostriker models), as suggested by D. S. Hall. It lies roughly 2 mag above the main sequence of the cluster. Insufficient information is available to establish whether, with an axial ratio of the secondary roughly equal to 2:1, the observed shape of the light curve during primary eclipse can be represented. The weakness of the K line in the combined spectrum is unexplained. (AIP)

• Research Organization: Department of Astronomy, University of California, Los Angeles
• OSTI ID: 7361371
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 205:2; 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
BINARY STARS
ECLIPSE
MAIN SEQUENCE STARS
MOTION
ROTATION
STAR CLUSTERS
STARS
VELOCITY