Photometry of the low accretion rate polar HS 1023+3900

Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany

Corresponding author: R. Schwarz, rschwarz@aip.de

Received: 12 March 2001
Accepted: 9 May 2001

Abstract

We present results from a photometric monitoring campaign of the new low magnetic CV HS 1023+3900. It showed the system at a constant brightness level during the half year of observations, confirming that it is permanently accreting at a low rate. Optical light curves are dominated by emission from two cyclotron spots in accordance with previously published spectroscopy. The timings of the primary maxima were used to derive a revised spin-period of 166.93 min. We estimated approximate locations of the accretion spots on the white dwarf by simple modeling of the R and I-band light curves. Interestingly, the dipole axis is perpendicular to the line connecting both stars and inclined into the orbital plane, an orientation quite different from that found in all other polars so far. We report the detection of a single flare event of mag lasting ~1 min, indicating chromospheric activity of the secondary.