Long-term decrease and cyclic variation in the orbital period of the eclipsing dwarf nova V2051 OPH

V2051 Oph is a deeply eclipsing dwarf nova with an orbital period below the period gap of cataclysmic variables (CVs). It has been photometrically monitored since 2008 June and 24 mid-eclipse times of the white dwarf have been obtained. The changes in the orbital period are investigated using all of...

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Autores principales: Qian, S. B., Han, Z. T., Fernández Lajús, Eduardo, Zhu, L. Y., Li, L. J., Liao, W. P., Zhao, E. G.
Formato: Articulo
Lenguaje:Inglés
Publicado: 2015
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/86916
Aporte de:
id I19-R120-10915-86916
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
binaries: eclipsing
planetary system
stars: dwarf nova
stars: evolution
stars: individuals (V2051 Oph)
spellingShingle Ciencias Astronómicas
binaries: eclipsing
planetary system
stars: dwarf nova
stars: evolution
stars: individuals (V2051 Oph)
Qian, S. B.
Han, Z. T.
Fernández Lajús, Eduardo
Zhu, L. Y.
Li, L. J.
Liao, W. P.
Zhao, E. G.
Long-term decrease and cyclic variation in the orbital period of the eclipsing dwarf nova V2051 OPH
topic_facet Ciencias Astronómicas
binaries: eclipsing
planetary system
stars: dwarf nova
stars: evolution
stars: individuals (V2051 Oph)
description V2051 Oph is a deeply eclipsing dwarf nova with an orbital period below the period gap of cataclysmic variables (CVs). It has been photometrically monitored since 2008 June and 24 mid-eclipse times of the white dwarf have been obtained. The changes in the orbital period are investigated using all of the available mid-eclipse times. A continuous period decrease with a rate of Ṗ =-5.93 10<sup>-10</sup> days yr<sup>-1</sup> was discovered to be superimposed on a periodic variation with a small amplitude of 0.<sup>d</sup>000329 and a period of 21.64 years. The standard theory predicted that the evolution of CVs below the period gap is driven by gravitational radiation. However, angular momentum loss (AML) via gravitational radiation is insufficient to explain this decrease, and additional AML via magnetic braking that is about five times the gravitational radiation rate is required. This is consistent with the theoretical requirement indicating that magnetic braking of the fully convective star is not completely stopped. The cyclic oscillation was interpreted as the variation of the arriving eclipse time via the presence of a third body because the required energy for the Applegate mechanism is much larger than that radiated from the secondary in 10 years. Its mass is derived as M<sub>3</sub>sin i' = 7.3 (±0.7) Jupiter mass. For orbital inclinations i' ≥ 30°.3, it would be a planetary object. The giant circumbinary planet is orbiting around V2051 Oph at an orbital separation of about 9.0 astronomical units (AU) in an eccentric orbit (e' = 0.37). These conclusions support the ideas that some planets could survive stellar late evolution and that dwarf novae are also planetary hosting stars.
format Articulo
Articulo
author Qian, S. B.
Han, Z. T.
Fernández Lajús, Eduardo
Zhu, L. Y.
Li, L. J.
Liao, W. P.
Zhao, E. G.
author_facet Qian, S. B.
Han, Z. T.
Fernández Lajús, Eduardo
Zhu, L. Y.
Li, L. J.
Liao, W. P.
Zhao, E. G.
author_sort Qian, S. B.
title Long-term decrease and cyclic variation in the orbital period of the eclipsing dwarf nova V2051 OPH
title_short Long-term decrease and cyclic variation in the orbital period of the eclipsing dwarf nova V2051 OPH
title_full Long-term decrease and cyclic variation in the orbital period of the eclipsing dwarf nova V2051 OPH
title_fullStr Long-term decrease and cyclic variation in the orbital period of the eclipsing dwarf nova V2051 OPH
title_full_unstemmed Long-term decrease and cyclic variation in the orbital period of the eclipsing dwarf nova V2051 OPH
title_sort long-term decrease and cyclic variation in the orbital period of the eclipsing dwarf nova v2051 oph
publishDate 2015
url http://sedici.unlp.edu.ar/handle/10915/86916
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