Swift/BAT detection of flaring activity from X-ray binary pulsar A 0535+262

ATel #14157; Manoj Mandal (MCC), Sabyasachi Pal (MCC/ICSP), Mangal Hazra (MCC), Arindam Jana (MCC), Bikram Bhunia (MCC) and Arnab Ghanta (MCC)
on 6 Nov 2020; 21:39 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Sabyasachi Pal (sabya.pal@gmail.com)

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We report detection of outburst from the accreting transient X-ray pulsar A 0535+262 (V725 Tau) using BAT onboard Swift satellite. The source was earlier reported to be in X-ray outburst multiple times (ATel #504, #595, #676, #1725, #2142, #2161, #2324, #2336, #2496, #2541 #2970, #6043, #6259, #6569, #7015, #7441, #8055, #8977). The X-ray pulsar has a spin period of 104 s (Rosenberg et al., 1975, Nature, 256, 628) and an orbital period of 110 d (Finger et al., 1996, ApJ, 459, 288).

The flux from the source started to increase from MJD 59151 (29th October 2020) and it is still increasing. The average flux between MJD 59140 and MJD 59151 in the 15-50 keV energy band was 0.006 cts/sec/cm2 (~30 mCrab) and on MJD 59159 (6th November 2020) it rose to 0.098+/-0.009 counts/cm2/sec (474 +/- 43.5 mCrab).

Since the intensity from the source is still increasing, further observations in all wavelengths are encouraged.