Eclipses of cataclysmic variables. II. U Geminorum

Journal Article · Thu Oct 01 00:00:00 EDT 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165674· OSTI ID:5546011

Zhang, E H; Robinson, E L

U Gem is an eclipsing dwarf nova with an orbital period of 4 h 15 m. High-speed, multicolor photometric observations of U Gem in its quiescent state were obtained. A program was used that synthesizes the light curves of cataclysmic variables to derive the properties of U Gem from its eclipses. Using radial velocity curves published by Wade (1981) and by Stover (1981), it was found that i = 69.7 + or - 0.7 deg, M1 = 1.12 + or - 0.13 solar masses, and M2 = 0.53 + or - 0.06 solar mass. The radial temperature distribution across the accretion disk in U Gem shows that the disk is a hollow ring around the white dwarf with R(out) = 0.30 + or - 0.04 and R(in) = 0.12 + or - 0.05 a, where a is the separation of the two stars. The temperature of the ring is 4800 + or - 300 K. The model also reproduces the published infrared light curves and ultraviolet spectral distributions of U Gem. A mass transfer rate of 7.8 x 10 to the -10th solar mass/yr is derived. The structure of the ring around the white dwarf is consistent with the current theories of accretion disk instabilities in dwarf novae. 39 references.

• Research Organization: McDonald Observatory, Austin, TX
• OSTI ID: 5546011
• Journal Information: Astrophys. J.; (United States), Vol. 321
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ERUPTIVE VARIABLE STARS
ECLIPSE
ACCRETION DISKS
DWARF STARS
HIGH TEMPERATURE
LUMINOSITY
MASS
MASS TRANSFER
NOVAE
PHOTOMETRY
RADIAL VELOCITY
ROCHE EQUIPOTENTIALS
STAR ACCRETION
ULTRAVIOLET SPECTRA
WHITE DWARF STARS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SPECTRA
STAR EVOLUTION
STARS
VARIABLE STARS
VELOCITY
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources