The H-alpha measurement of the Be X-ray binary RX J0209.6-7427 with the Southern African Large Telescope (SALT)
ATel #13307; I. M. Monageng (SAAO/UCT), D. Buckley (SAAO), M. J. Coe (Southampton), P. Gandhi (Southampton), J. A. Paice (Southampton, IUCAA), P. A. Charles (Southampton), R. Misra (IUCAA), N. T. Thomas (CHRIST - Deemed to be University)
on 22 Nov 2019; 13:37 UT
Credential Certification: Itumeleng Monageng (itu@saao.ac.za)
Subjects: Optical, X-ray, Binary, Transient
Observations with the MAXI/GSC nova alert system performed on 20 November 2019 revealed an uncatalogued X-ray transient source in the Magellanic Bridge with a steady increase in flux which was designated MAXI J0206-749 (Atel #13300). Follow up observations with Swift on 21 November 2019 (Atel #13303) showed that the source is positionally coincident with a known Be X-ray binary, RX J0209.6-7427.
We obtained an optical spectrum of RX J0209.6-7427 on 21 November 2019 at 20:37 UT using the Southern African Large Telescope (SALT) under the transient follow up program. The Robert Stobie Spectrograph was used with the PG1800 grating with an exposure time of 1600 s (resolution ~ 4.7 Angstroms) covering the wavelength range 6000-7250 Angstroms, where the the H-alpha line is seen in emission. The measured FWHM of the H-alpha line for this observation is 10.247 \pm 0.015 Angstroms and the EW is -10.70 \pm 0.24 Angstroms, which is comparable to measurements previously obtained for this source (Kahabka and Hilker 2005).
