2017/09/08 by S. Qian, S. -B. Qian, Z. -T. Han +16
Engineering · Physics and Astronomy · #Accretion (finance) #Astronomical Observations and Instrumentation #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Cataclysmic variable star #Dwarf nova #Gamma-ray bursts and supernovae #Intermediate polar #Light curve #Physics #Stars #White dwarf #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/aa8bb8
16 pages, 6 figures, accepted for publication in ApJ
arxiv created 2017/09/08 · openalex created_date 2017/09/15 · openalex publication_date 2017/10/20 · arxiv updated 2017/11/01 · openalex updated_date 2026/08/06
Abstract 1SWASP J162117.36+441254.2 was originally classified as an EW-type binary with a period of 0.20785 days. However, it was detected to have undergone a stellar outburst on 2016 June 3. Although the system was later classified as a cataclysmic variable (CV) and the event was attributed as a dwarf nova outburst, the physical reason is still unknown. This binary has been monitored photometrically since 2016 April 19, and many light curves were obtained before, during, and after the outburst. Those light and color curves observed before the outburst indicate that the system is a special CV. The white dwarf is not accreting material from the secondary and there are no accretion disks surrounding the white dwarf. By comparing the light curves obtained from 2016 April 19 to those from September 14, it was found that magnetic activity of the secondary is associated with the outburst. We show strong evidence that the L 1 region on the secondary was heavily spotted before and after the outburst and thus quench the mass transfer, while the outburst is produced by a sudden mass accretion of the white dwarf. These results suggest that J162117 is a good astrophysical laboratory to study stellar magnetic activity and its influences on CV mass transfer and mass accretion.