1999/03/31 by Cynthia S. Froning, C. S. Froning, E. L. Robinson +2 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysical Phenomena and Observations #High-pressure geophysics and materials #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1086/307713
Corrected minor typos, 7/99. Paper in press, will appear in September 20, 1999 issue of the ApJ. Accepted for publication in The Astrophysical Journal; 14 pages, 12 figures; Latex macro emulateapj.sty
arxiv created 1999/07/07 · openalex publication_date 1999/09/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We present near-infrared, H -band (1.45-1.85 μm) observations of an eclipsing dwarf nova, IP Peg, in quiescence. The light curves are composed of ellipsoidal variations from the late-type secondary star and emission from the accretion disk and the bright spot. The light curves have two eclipses: a primary eclipse of the accretion disk and the bright spot by the companion star, and a secondary eclipse of the companion star by the disk. The ellipsoidal variations of the secondary star were modeled and subtracted from the data. The resulting light curve shows a pronounced double-hump variation. The double-hump profile resembles those seen in the light curves of WZ Sge and AL Com and likely originates in the accretion disk. The primary eclipse was modeled using maximum entropy disk mapping techniques. The accretion disk has a flat intensity distribution and a cool brightness temperature ( T br ≃ 3000 K) in the near-infrared. Superimposed on the face of the disk is the bright spot ( T br ≃ 10,000 K); the position of the bright spot is different from the observed range of visible bright spot positions. The near-infrared accretion disk flux is dominated by optically thin emission. The secondary eclipse indicates the presence of some occulting medium in the disk, but the eclipse depth is too shallow to be caused by a fully opaque accretion disk.