SRG/ART-XC detection of the outburst in historic SMC pulsar XTE J0111.2-7317 (SXP31)
ATel #17163; A. Semena(1), I. Mereminskiy(1), S. Molkov(1), A. Lutovinov(1), A. Tkachenko(1), A. Shtykovsky (1) (1:IKI RAS, Moscow)
on 26 Apr 2025; 20:44 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Andrey Semena (san@iki.rssi.ru)
Subjects: Binary, Neutron Star, Transient, Pulsar
During the on-going all-sky survey, on Apr.26, 2025, the Mikhail Pavlinsky ART-XC telescope onboard the SRG observatory detected a bright X-ray transient at the position of RA, Dec = 17.7852, -73.2787 (J2000, positional uncertainty is 15â, 90%). Observed X-ray flux was 1.2(+/-0.2)x10^-10 erg/cm2/s in the 4-12 keV band.
The position of the transient is 3" off the position of the historical X-ray transient XTE J0111.2-7317 - BeXRB in the Small Magellanic Cloud, which went into a giant outburst in 1998.
Assuming the distance to the SMC to be 60 kpc we estimated current luminosity of the source to be 5x10^37 erg/s, which might suggest the ongoing type II outburst.
Additional observations are needed to measure the current rotation period and to trace the outburst profile.
The Mikhail Pavlinsky ART-XC telescope is the X-ray telescope on board the SRG observatory which was launched from the Baikonur cosmodrome on 13 July 2019 by the Proton rocket. We thank the Swift team for their rapid response.
