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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The light curve of V921 Her in ultraviolet band observed by the Lunar-basedUltraviolet Telescope (LUT) is analyzed by the Wilson-Devinney code. Oursolutions conclude that V921 Her is an early type marginal contact binarysystem with an additional close-in component. The binary system is under poorthermal contact with a temperature difference of nearly $700K$ between the twocomponents. The close-in component contributes about $19\,\%$ of the totalluminosity in the triple system. Combining the radial velocity study togetherwith our photometric solutions, the mass of the primary star and secondary oneare calculated to be $M_1 = 1.784(\pm0.055)M_\odot$, $M_2 =0.403(\pm0.012)M_\odot$. The evolutionary scenario of V921 Her is discussed.All times of light minimum of V921 Her available in the bibliography are takeninto account and the $O - C$ curve is analyzed for the first time. The mostprobable fitting results are discussed in the paper, which also confirm theexistence of a third component ($P_3=10.2$ year) around the binary system. Theperiod of V921 Her is also undergoing a continuously rapid increase at a rateof $dP/dt=+2.79\times{10^{-7}}day\cdot year^{-1}$, which may due to masstransfer from the less massive component to the more massive one.

The Photometric Investigation of V921 Her using the Lunar-based Ultraviolet Telescope of Chang'e-3 mission