文章基本信息

标题：Cyclic Period Oscillation of the Eclipsing Dwarf Nova DV UMa
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作者：Z.-T Han ; S.-B Qian ; Voloshina Irina 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2017
卷号：153
期号：5
DOI：10.3847/1538-3881/aa6c2a
语种：English
出版社：American Institute of Physics
摘要：DV UMa is an eclipsing dwarf nova with an orbital period of ~2.06 hr, which lies just at the bottom edge of the period gap. To detect its orbital period changes, we present 12 new mid-eclipse times by using our CCD photometric data and archival data. The latest version of the O–C diagram, combined with the published mid-eclipse times in quiescence, and spanning ~30 years, was obtained and analyzed. The best fit to those available eclipse timings shows that the orbital period of DV UMa is undergoing a cyclic oscillation with a period of years and an amplitude of s. The periodic variation most likely arises from the light-travel-time effect via the presence of a circumbinary object, because the required energy to drive the Applegate mechanism is too high in this system. The mass of the unseen companion was derived as . If the third body is in the orbital plane (i.e., ) of the eclipsing pair, this would indicate it is a brown dwarf. This hypothetical brown dwarf is orbiting its host star at a separation of ~8.6 au in an eccentric orbit (e = 0.44).
关键词：binaries: close;binaries: eclipsing;stars: dwarf novae;stars: individual (DV UMa)