Observed Low States in DQ Herculis Systems
Abstract
The Harvard Plate Collection was used to search for the existence of low accretion rate states in three DQ Her-type cataclysmic variables. The search shows that DQ Her systems may show the typical low-state behavior of AM Her or VY Scl systems. However, there are also DQ Her systems which show little or no reduction in accretion rate over long periods of time. In plotting the amplitude range of the low- to high-state behavior as a function of the orbital period, it is apparent that the AM Her systems below the period gap follow a decreasing trend of activity as the period gap is approached. If this behavior is interpreted as a measure of the accretion rate, this trend is opposite to the relationships calculated for gravitational radiation and magnetic braking below the gap by Hameury et al. (1988). Above the gap the amplitude generally increases with orbital period of VY Scl systems, with a steeper relationship than for magnetic braking.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- December 1988
- DOI:
- 10.1086/132358
- Bibcode:
- 1988PASP..100.1522G
- Keywords:
-
- Binary Stars;
- Cataclysmic Variables;
- Novae;
- Stellar Mass Accretion;
- Stellar Systems;
- Light Curve;
- Stellar Magnitude;
- Astronomy;
- STARS: U GEMINORUM