Optical observations of the Be/gamma-ray binary MWC 148
ATel #11257; K. A. Stoyanov, V. V. Dimitrov, R. K. Zamanov, N. I. Petrov, Y. M. Nikolov (Institute of Astronomy and NAO, Bulgarian Academy of Sciences, Bulgaria), D. V. Marchev (Department of Physics, Shumen University, Bulgaria)
on 5 Feb 2018; 15:06 UT
Credential Certification: Kiril Stoyanov (kstoyanov@astro.bas.bg)
Subjects: Optical, Binary, Black Hole, Neutron Star
Following ATel#11223 and ATel#11233, we performed optical spectroscopic and photometric observations of the gamma-ray binary MWC 148 (HESS J0632+057).
On the nights of 2018 Jan 27 and 2018 Feb 1 we obtained spectra with the ESpeRo spectrograph (Bonev et al. 2017, BlgAJ, 26, 67) on the 2m RCC telescope at Rozhen NAO, Bulgaria. Our observations show that the H-alpha emission line is variable between -70 km/s and +200 km/s, similar to the previous spectra (Fig.1). The equivalent width of the H-alpha emission line is about 44 Å.
We observed MWC 148 in B and V bands on the night of 2018 Jan 26 with the 50/70cm Schmidt telescope at Rozhen NAO. We obtained the following magnitudes — in B band 9.66 ± 0.05 and in V band 9.12 ± 0.04, practically identical with the values given in the SIMBAD database.
This research was partially supported by contracts DN 08-1/2016 and DN 18/13-12.12.2017 with the National Science Fund.
Fig.1 H-alpha emission lines of MWC 148