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G. J. Peters (USC), R. S. Polidan (NASA's GSFC)
RY Per (HD~17034, B4~V + F7~II-III, P=6.86 d) is a massive interacting binary (6.25~M\odot + 1.60~M\odot, Olson & Plavec 1997, AJ, 113, 425) that displays a variable weak accretion disk that emits in H\alpha (Barai, et al., preprint). FUSE observations of this system, carried through in 2002 October at phases 0.20, 0.57, and 0.97 and during its total eclipse on 2002 December~8 are presented. The totality data were binned into two phase intervals: 0.0056-0.9976 (after second contact) and 0.0052-0.0089 (just before third contact). Both eclipse observations reveal broad, prominent emission lines of N~III (UV1, \lambda\lambda990-992~Å), O~VI (UV1, \lambda\lambda1032,1038~Å), N~II (UV1, \lambda\lambda1084-1086~Å), Si~III (UV5, \lambda\lambda1108,1109,1113~Å), Si~IV(UV3, \lambda\lambda1122,1138~Å), and Fe~III (UV1, \lambda\lambda1122-32~Å). Emission from C~III (UV4, \lambda1176~Å) seen during totality in FUSE observations of the Algol binaries V356~Sgr and TT~Hya is conspicuously absent. C~III (UV1, \lambda977~Å) is also absent. This observation combined with the strong presence of N~II, III emission suggests that material processed through the CNO cycle in the mass loser is now being transferred to the B star. The FUSE data imply that the emitting plasma is hot (~100,000-300,000~K) and located above/below the orbital plane. The source of this apparent bipolar flow (also seen in V356~Sgr and TT~Hya) may be the splash region detected near phase 0.5 in IUE observations of the N~V resonance line, but absorption features from this region were not seen in the non-eclipse FUSE observations. A model for the circumstellar material in this system will be presented and the FUSE observations will be compared with those of V356~Sgr and TT~Hya.
GJP is grateful for support from NASA Grant NAG5-12253.
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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.