H-alpha line profile variation in the Be/X-ray binary A0535+262
ATel #7030; Iain Steele (Liverpool JMU)
on 5 Feb 2015; 22:24 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. The source is currently reported in X-ray outburst (ATel #7015). The FRODOSpec observations over the period December 2013 to February 2015 confirm the decline of the H-alpha emission equivalent width reported in ATel #7029:
DATE H-alpha EW
2013 Dec 22 13.9
2014 Sep 12 10.3
2014 Dec 31 9.3
2015 Feb 03 8.4
The line profile of H-alpha is also seen to vary over this timescale. All profiles are single peaked, however
an asymmetry can be seen to move from the blue to the red side of the spectrum over the 14 month period.
In December 2013 the profile had an overall FWHM of ~200 km/s with a significant blue enhancement at -100 km/s. In September 2014 the profile was symmetrical with a wider FWHM of ~350 km/s. The spectra from late December 2014 and early February 2015 are similar, with a FWHM ~200 km/s and a significant red enhancement at +100 km/s.
Liverpool Telescope