Accretion-disc precession in UX Ursae Majoris
We report the results of a long campaign of time-series photome try on the nova-like variable UX Ursae Majoris during 2015. It spanned 150 nights, with ~ 1800 h ours of coverage on 121 separate nights. The star was in its normal ‘high state’ near m agnitude V = 13, with slow waves in the light curve...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universidad de Huelva (UHU) |
| Repositorio: | Arias Montano. Repositorio Institucional de la Universidad de Huelva |
| Idioma: | inglés |
| OAI Identifier: | oai:ariasmontano.uhu.es:10272/12243 |
| Acceso en línea: | http://hdl.handle.net/10272/12243 |
| Access Level: | acceso abierto |
| Palabra clave: | Accretion, accretion discs Binaries: close Stars: individual: UX Ursae Majoris Novae, cataclysmic variables |
| Sumario: | We report the results of a long campaign of time-series photome try on the nova-like variable UX Ursae Majoris during 2015. It spanned 150 nights, with ~ 1800 h ours of coverage on 121 separate nights. The star was in its normal ‘high state’ near m agnitude V = 13, with slow waves in the light curve and eclipses every 4.72 hours. Remarkably, t he star also showed a nearly sinusoidal signal with a full amplitude of 0.44 mag and a perio d of 3.680± 0.007 d. We interpret this as the signature of a retrograde precession (wobble) of th e accretion disc. The same period is manifest as a ±33 s wobble in the timings of mid-eclipse, indic ating that the disc’s centre of light moves with this period. The star also showed strong ‘negative s uperhumps’ at frequencies ft) or b + N and 2ft) or b + N, where w or b and N are respectively the orbital and precession frequencies. It is possible that these powerful signals have been present, unsu spected, throughout the more than 60 years of previous photometric studies. |
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