New X-ray transient IGR J17533-2928 discovered by INTEGRAL
ATel #14425; S. A. Grebenev and I. A. Mereminskiy (Space Research Institute, Moscow)
on 27 Feb 2021; 09:39 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Sergei Grebenev (sergei@hea.iki.rssi.ru)
Subjects: X-ray, Request for Observations, Transient
During our observations of the Galactic center region with INTEGRAL on Feb. 13-23, 2021, a weak X-ray source was marginally (S/N=7.6) detected with the IBIS/ISGRI telescope in the 20-80 keV band. Taking into account its best fit position, R.A.=17h53m18s (268.323 deg), Decl.=-29d28m30s (-29.475 deg), equinox 2000.0, uncertainty 2', we named the source IGR J17533-2928. The only known nearby source, AX J1754.0-2929, is located more than 9' off this position.
The mean photon flux was 12.4+/-1.7 mCrab. Some signs of the variability were detected on a time scale of days (the source flux was 13.8+/-3.4 mCrab on Feb. 13, 15.4+/-4.0 mCrab on Feb. 17, and 8.8+/-2.4 mCrab on Feb. 23). The other INTEGRAL telescope, JEM-X, sensitive in the softer X-ray band, was unable to detect the source at a confident level. The next set of our INTEGRAL observations of the region is scheduled for Feb. 28.
We encourage follow-up observations of this source by other instruments.
