[Previous] | [Session 62] | [Next]
T. E. Harrison, H. Osborne, J. J. Johnson (NMSU), S. B. Howell (PSI), D. M. Gelino (UCSD)
One of the most difficult parameters to measure for cataclysmic variables are their orbital inclinations. Before we can determine the masses of the stellar components in these systems, or realistically model their accretion disks and outburst luminosities, we must know their orbital inclinations. We have begun a program using SQIID on the KPNO 2.1 m to determine the orbital inclinations for a wide variety of cataclysmic variables. Due to the distorted shape of the secondary star, the light curves of cataclysmic variables exhibit ``ellipsoidal'' variations as the secondary orbits the white dwarf primary. By modeling these variations with a sophisticated light-curve modeling program, such as WD98, we can determine fairly precise orbital inclinations for these binaries. Because the secondary star usually dominates the infrared luminosity of a cataclysmic variable, it is much easier to detect pure ellipsoidal variations in the infrared. KPNO's SQIID allows us to obtain simultaneous JHK light curves. We present the initial results from our program. These infrared data will eventually be combined with near-simultaneous, orbital phase-resolved optical data to help eliminate the effects of emission from the non-stellar components in these systems.