Optical activity of the high-mass X-ray binary SAX J2103.5+4545.
ATel #10190; T. S. Grishina, E. G. Larionova, S. S. Savchenko, V. M. Larionov (St. Petersburg University, Russia)
on 21 Mar 2017; 20:31 UT
Credential Certification: V. Larionov (firstname.lastname@example.org)
Subjects: Optical, X-ray, Binary, Neutron Star, Star
Referred to by ATel #: 10249
We report on the renewed optical activity of the high-mass X-ray binary system SAX J2103.5+4545. The source is monitored with the 0.4-m LX-200 (St.Petersburg, Russia) and 0.7-m AZT-8 (CrAO, Russia) telescopes. In the night of 2017-02-06 (MJD 57791.2) the brightness of the optical counterpart was R= 13.46+/-0.02 and in the night of 2017-03-17 (MJD 57830.6) its brightness reached R= 13.15+/-0.02, as compared to quiescent level of R= 13.61+/-0.02 in the night 2016-11-18 (MJD 57711.3). Optical light curve of SAX J2103.5+4545 is presented here. The previous optical high state observed in January 2016 was followed by the onset of X-ray activity of the source, see Swift/BAT light curve. The new optical brightening is also accompanied by X-ray outburst that has just started. Multiwavelength observations of the system are desirable for monitoring of its activity.