Ultraviolet study of the active interacting binary star R Arae using archival IUE data

• Published in: Monthly notices of the Royal Astronomical Society 2010-01, Vol.401 (2), p.913-923
• Main Authors: Reed, Phillip A., McCluskey, George E., Kondo, Yoji, Sahade, Jorge, Guinan, Edward F., Giménez, Alvaro, Caton, Daniel B., Reichart, Daniel E., Ivarsen, Kevin M., Nysewander, Melissa C.
• Format: Article
• Language: English
• Subjects: accretion; accretion discs; Accretion disks; accretion, accretion discs; Astronomy; binaries: close; circumstellar matter; Double stars; Earth, ocean, space; Exact sciences and technology; Spectrum analysis; Star & galaxy formation; stars: evolution; techniques: spectroscopic; Ultraviolet astronomy; ultraviolet: stars
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2009.15741.x

The eclipsing and strongly interacting binary star system R Arae (HD 149730) is in a very active and very short-lived stage of its evolution. R Ara consists of a B9V primary and an unknown secondary. We have collected the International Ultraviolet Explorer (IUE) archival data on R Ara, with most of the data being studied for the first time. There are 117 high-resolution IUE spectra taken in 1980, 1982, 1985, 1989 and 1991. We provide photometric and spectroscopic evidence for mass transfer and propose a geometry for the accretion structure. We use colour-scale radial velocity plots to view the complicated behaviour of the blended absorption features and to distinguish the motions of hotter and cooler regions within the system. We observed a primary eclipse of R Ara in 2008 and have verified that its period is increasing. A model of the system and its evolutionary status is presented.