Evidence of a brown dwark in the eclipsing dwarf nova Z Chamaeleonis
We presented three new CCD observations of light minima of Z Chamaeleonis. All 187 available times of light minimum including 37 photographic data are compiled, and a new orbital period analysis is made by means of the standard O − C technique. The O − C diagram of Z Chamaeleonis presents a cyclical...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2009 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/42813 |
| Acceso en línea: | http://hdl.handle.net/11336/42813 |
| Access Level: | acceso abierto |
| Palabra clave: | Eclipsing binaries Novae Cataclysmic variables Z Chamaeleonis (estrella) https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Sumario: | We presented three new CCD observations of light minima of Z Chamaeleonis. All 187 available times of light minimum including 37 photographic data are compiled, and a new orbital period analysis is made by means of the standard O − C technique. The O − C diagram of Z Chamaeleonis presents a cyclical periodic change of ∼ 32.57 yr with a high significance level. We attempted to apply two plausible mechanisms (i.e., Applegate’s mechanism and light travel-time effect) to explain the cyclical variations of orbital period shown in the O–C diagram. Although the previous works suggested that solar-type magnetic cycles in the red dwarf are the best explanation, the analysis of Applegate’s mechanism in this paper presents a negative result. Accordingly, a light travel-time effect is proposed, and a brown dwarf as a tertiary component orbiting around dwarf nova Z Chamaeleonis is derived with a significance level of 81.6%, which may be a plausible explanation of the periodic variation in the systemic velocity of Z Chamaeleonis in superoutburst. |
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