The 2015 superoutburst of QZ Virginis: Detection of growing superhumps between the precursor and main superoutburst
Abstract
We report on time-resolved photometry of the 2015 February-March superoutburst of QZ Virginis. The superoutburst consisted of a separated precursor, main superoutburst, and rebrightening. We detected superhumps with a period of 0.061181(42) d between the precursor and main superoutburst. Based on analyses of period changes and amplitudes of superhumps, the observed superhumps were identified as growing superhumps (stage A superhumps). The duration of the stage A superhumps was about 5 d, unusually long for SU UMa-type dwarf novae. Using the obtained stage A superhump period, we estimated the mass ratio of QZ Vir to be 0.108(3). This value suggests that QZ Vir is an SU UMa-type dwarf nova evolving toward the period minimum. Based on the present and previous observations regarding long-lasting stage A superhumps, the time scale for stage A superhumps is likely to be determined by the mass ratio of the system and the temperature of the accretion disk.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- August 2017
- DOI:
- 10.1093/pasj/psx055
- arXiv:
- arXiv:1711.06076
- Bibcode:
- 2017PASJ...69...72I
- Keywords:
-
- accretion;
- accretion disks;
- stars: dwarf novae;
- stars: individual (QZ Virginis);
- stars: novae;
- cataclysmic variables;
- stars: oscillations;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 12 pages, 6 figures, published for PASJ, 69, 72