Title: Observations of V0332+53 during the 2015 Outburst using Fermi/GBM, MAXI, Swift, and INTEGRAL Author: Zachary A. Baum, Michael L. Cherry, James Rodi
We present the lightcurves, spectra, and hardness-intensity diagram (HID) of the high mass X-ray binary V0332+53 using Fermi/GBM, MAXI, Swift/BAT, and INTEGRAL through its 2015 Type II outburst. We observe characteristic features in the X-ray emission (2-50 keV) due to periastron passages, the dynamical timescale of the accretion disc, and changes within the accretion column between a radiation-dominated flow and a flow dominated by Coulomb interactions. Based on the HID and the light curves, the critical luminosity is observed to decrease by ~5-7 percent during the outburst, signalling a decrease in the magnetic field.
BQ Camelopardalis is a Be/X-ray binary system consisting of a variable type star and a neutron star. BQ Camelopardalis is the optical counterpart of the transient X-ray pulsar V0332+53. The star varies between magnitude 15.2 and 15.9 V, and X-ray outbursts are associated with the maxima of optical brightness. The system was last in outburst on the 25th October, 2009.
Position(2000): RA = 03h34m59.89s, Dec = 53° 10' 23.6"
Title: Long-term optical observations of Be/X-Ray binary system V0332+53 Authors: U. Kiziloglu, N. Kiziloglu, A. Baykal, S. K. Yerli, M. Ozbey
We have been monitoring the binary system V0332+53 (optical counterpart is BQ Cam) since 2004 using 45 cm ROTSEIIId telescope and RTT150 (Russian-Turkish 1.5 m Telescope) located at Bakirlitepe, Antalya, Turkey. We report on the long-term variability of this system up to the present date. There exists a fading of 0.2 mag in the light of BQ Cam after MJD 53400. The fading in the light curve of BQ Cam could be due to a decrease in the density or in the size of the circumstellar disk. We present optical spectroscopic observations obtained before (at MJD 54730) and during (at MJD 54768) the new X-ray activity reported by Krimm et al. (2008). The observed Ha line profiles were single-peaked and almost symmetric. The present EW values are found to be similar to the ones observed during the fading of infrared magnitudes of Negueruela et al. (1999). Ha emission lines were found to be red-shifted by ~140 km/s which were larger than the findings of Corbet et al. (1986). We suggest that brightening of the disk after MJD 54700 may be due to the precession of the disk.
On the 17th October, 2008, the Swift satellite detected increased activity in the 15-50 keV band for the transient pulsar and High Mass X-ray Binary V0332+53. The Be/neutron star system contains the variable BQ Cam, which the optical counterpart of the X-ray binary source V0332+53.