English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

1SWASP\,J162117.36$+$441254.2 was originally classified as an EW-type binarywith a period of 0.20785\,days. However, it was detected to have undergone astellar outburst on June 3, 2016. Although the system was latter classified asa cataclysmic variable (CV) and the event was attributed as a dwarf-novaoutburst, the physical reason is still unknown. This binary has been monitoredphotometrically since April 19, 2016 and many light curves were obtainedbefore, during and after the outburst. Those light and color curves observedbefore the outburst indicate that the system is a special CV. The white dwarfis not accreting material from the secondary and there are no accretion diskssurrounding the white dwarf. By comparing the light curves obtained from April19 to September 14, 2016, it was found that magnetic activity of the secondaryis associated with the outburst. We show strong evidence that the $L_1$ regionon the secondary was heavily spotted before and after the outburst and thusquench the mass transfer, while the outburst is produced by a sudden massaccretion of the white dwarf. These results suggest that J162117 is a goodastrophysical laboratory to study stellar magnetic activity and its influenceson CV mass transfer and mass accretion.

A New Stellar Outburst Associated with the Magnetic Activities of the K-type Dwarf in a White-dwarf Binary