H-alpha variability of the Be star in the HMXRB A0535+262
ATel #8487; I. A. Steele (Liverpool JMU)
on 31 Dec 2015; 15:49 UT
Credential Certification: Iain Steele (iainsteele@mac.com)
Subjects: Optical, X-ray, Binary, Transient, Pulsar
The Be star in the high mass X-ray binary A0535+262 is the subject of occasional spectroscopic monitoring with the FRODOSpec spectrograph on the Liverpool Telescope at medium (R=5000) resolution. In ATel #8446 Giovannelli et al. report weak enhancement of the V band flux on 2015 Dec 19 which may signal an forthcoming X-ray outburst.
We have obtained optical spectroscopy of the system on the following dates and measure a small increase in the equivalent width of the H-alpha emission line.
2015 Dec 19 at 05:09UT EW=9.2 Ang.
2015 Dec 20 at 21:00 UT EW=9.4 Ang.
2015 Dec 28 at 22:37 UT EW=9.8 Ang.
The profile of the H-alpha line in all three spectra is similar. The overall FWHM is ~300 km/s and a small red enhancement to the peak at +50km/s from the line centre is apparent. Combination with the previous FRODOSpec profiles described in ATel #
7030 from 2013 Dec through to 2015 Feb indicates the possible presence of a V/R variability cycle with a period ~3 to 4 years.
Liverpool Telescope
