High-Amplitude, Rapid Photometric Variation of the New Polar Master OT J132104.0+560957.8
Abstract
Polars are cataclysmic variables (CVs) in which the magnetic field of the white dwarf (WD) synchronizes the WD s spin period with the orbital period of the binary (see Cropper (1990) for a thorough review). In contrast to non-magnetic CVs, there is no accretion disk in a polar. Instead, as the accretion stream flows from the L1 point toward the WD, the magnetic pressure from the WD rapidly increases until it matches the stream s ram pressure. The stream then threads onto the WD s magnetic field lines, which channel the captured material onto cyclotron-emitting accretion regions near the WD s magnetic poles. Because cyclotron emission is heavily beamed, it appears brightest when the observer s line of sight is perpendicular to the field lines of the emitting material; thus, changes in the viewing angle of the cyclotron-emitting region can produce dramatic photometric variability modulated at the WD s spin period (e.g., Gansicke et al. 2001). A polar can undergo a precipitous drop in optical brightness if the accretion region rotates behind the limb of the WD or is eclipsed by the donor star.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 05, 2015
- Accession Number
- ADA622952
Entities
People
- Benjamin Rose
- Colin Littlefield
- Colin Mcclelland
- Katrina Magno
- Marc Murison
- Peter Garnavich
- Shanel Deal
Organizations
- United States Naval Observatory Flagstaff Station