Publications of the Astronomical Society of the Pacific · 1983 · 32 citations · 0 references
Natural SciencesAstronomyPhysicsAstrophysicsPlanetary AstronomyStellar AstronomyBinary Star DynamicsBinary Star OrbitsBinary Star SystemsStellar EvolutionStellar RotationStellar StructureAngular Momentum ConservationApsidal MotionBinary System DynamicsEclipse Timing VariationsEclipsing Binary StarsNova OutburstsOrbital PeriodRelative Orbital Motion
Seventeen new timings of primary eclipse minimum for the dwarf nova, U Gem, are reported. The orbital period of the binary system is seen as quasi-periodic. Among the possible causes of the ephemeris variability are nonconservative mass transfer, nonconservation of orbital angular momentum, the relative motion of the hot spot within the system, apsidal motion, and the existence of a third star. U Gem is found to exhibit the following interesting features: flickering (indicating possible spasmodic mass transfer); the probable existence of a disk, allowing storage of considerable rotational angular momentum; occasional swelling of the disk, suggesting variable momentum storage; and outbursts.