The massive Wolf-Rayet binary SMC WR7

We present a study of optical spectra of the Wolf-Rayet star AzV 336a (= SMC WR7) in the Small Magellanic Cloud. Our study is based on data obtained at several Observatories between 1988 and 2001. We find SMC WR7 to be a double-lined WN+O6 spectroscopic binary with an orbital period of 19.56 d. The...

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Detalles Bibliográficos
Autores: Niemelä, Virpi Sinikka, Massey, P., Testor, G., Giménez Benítez, Sixto
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2002
País:Argentina
Institución:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/84657
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84657
Access Level:acceso abierto
Palabra clave:Ciencias Astronómicas
Binaries: spectroscopic
Stars: individual: AzV 336a (=SMC WR7)
Stars: Wolf-Rayet
Descripción
Sumario:We present a study of optical spectra of the Wolf-Rayet star AzV 336a (= SMC WR7) in the Small Magellanic Cloud. Our study is based on data obtained at several Observatories between 1988 and 2001. We find SMC WR7 to be a double-lined WN+O6 spectroscopic binary with an orbital period of 19.56 d. The radial velocities of the He absorption lines of the O6 component and the strong He II emission at λ4686 Å of the WN component describe anti-phased orbital motions. However, they show a small phase shift of ∼ 1 d. We discuss possible explanations for this phase shift. The amplitude of the radial velocity variations of He II emission is twice that of the absorption lines. The binary components have fairly high minimum masses, ∼ 18 and 34 M⊙ for the WN and O6 components, respectively.