Modeling UX Ursae Majoris: An Abundance of Challenges
نویسندگان
چکیده
منابع مشابه
The distribution of calcium on the surface of Ursae Majoris: an abundance distribution Doppler image
We present a surface abundance Doppler image of singly–ionized calcium for the Bp star UMa based on high signal-to-noise CCD spectra. This map shows striking similarities to that of oxygen (Rice et al. 1997) and perhaps iron (Rice & Wehlau 1990). The Ca II 866.2 nm line has allowed us to obtain a detailed surface abundance map of calcium for UMa. The calcium abundance map has been used to locat...
متن کاملInfrared Observations of AR Ursae Majoris: Modeling the Ellipsoidal Variations
We have obtained time-series infrared photometry for the highly magnetic cataclysmic variable AR UMa. Our J and K’ band observations occurred during a low state and they show a distinctive double-humped structure. Using detailed models for the expected ellipsoidal variations in the infrared due to the non-spherical secondary star, we find that the most likely value for the system inclination is...
متن کاملHST/FOS Eclipse Observations of the Nova-like Cataclysmic Variable UX Ursae Majoris
We present and analyze Hubble Space Telescope observations of the eclipsing nova-like cataclysmic variable UX UMa obtained with the Faint Object Spectrograph. Two eclipses each were observed with the G160L grating (covering the ultraviolet waveband) in August of 1994 and with the PRISM (covering the near-ultraviolet to near-infrared) in November of the same year. The system was ∼50% brighter in...
متن کاملUnusual Phase Reversal of Superhumps in ER Ursae Majoris
We studied the evolution of superhumps in the peculiar SU UMa-type dwarf nova, ER UMa. Contrary to the canonical picture of the SU UMa-type superhump phenomena, the superhumps of ER UMa show an unexpected phase reversal during the very early stage (∼5 d after the superoutburst maximum). We interpret that a sudden switch to so-called late superhumps occurs during the very early stage of a supero...
متن کاملThe dynamical stability of W Ursae Majoris-type systems
Theoretical study indicates that a contact binary system would merge into a rapidly rotating single star due to tidal instability when the spin angular momentum of the system is more than a third of its orbital angular momentum. Assuming that W UMa contact binary systems rigorously comply with the Roche geometry and the dynamical stability limit is at a contact degree of about 70%, we obtain th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2008
ISSN: 0004-637X,1538-4357
DOI: 10.1086/592104