VLT optical observations of V821 Ara(=GX339-4) in an extended ``off'' state

Shahbaz, T.; Fender, R.; Charles, P. A.
Referencia bibliográfica

Astronomy and Astrophysics, v.376, p.L17-L21 (2001)

Fecha de publicación:
9
2001
Número de autores
3
Número de autores del IAC
1
Número de citas
51
Número de citas referidas
45
Descripción
We report on low-resolution spectroscopy of GX339-4 during its current, extended X-ray ``off'' state in May 2000 (r=20.1) obtained with the VLT Focal Reducer/low dispersion Spectrograph (FORS1). Although we do not positively detect the secondary star in GX339-4 we place an upper limit of 30 percent on the contribution of a ``normal'' K-type secondary star spectrum to the observed flux. Using this limit for the observed magnitude of the secondary star, we find a lower limit for the distance of GX339-4 to be 5.6 kpc. Based on observations performed at the European Southern Observatory, Paranal, Chile.