A Spectral History of the Polar EF Eridanus
Abstract
EF Eridanus was one of the brightest X-ray polars in the sky. For the past 7 years, it has been in an extended low state. The current almost complete lack of mass transfer from the secondary star onto the magnetic white dwarf has allowed us to obtain unprecedented views of the component stars. The binary no longer resembles a cataclysmic variable but appears as a cool magnetic white dwarf in the optical and as a brown dwarf-like object in the infrared. The white dwarf has an effective temperature of only 9500K and a magnetic field strength of around 20 MG while the secondary star is ~0.04 solar masses, has an effective temperature of near 1000K, and is approximately an L4 class object. We present a multi-wavelength spectral history of this unique binary concentrating on our recent optical and infrared observations.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AAS...201.4008H