Fermi/GBM detects outburst from Be/X-ray binary 2S 1553-542
ATel #16839; Peter Jenke (UAH), Christian Malacaria (INAF-OAR)
on 2 Oct 2024; 15:57 UT
Credential Certification: Peter Jenke (peter.a.jenke@nasa.gov)
Subjects: X-ray, Gamma Ray, Binary, Neutron Star, Transient, Pulsar
The Fermi/GBM accreting pulsar program is currently detecting pulsations from the transient Be/X-ray binary 2S 1553-54. The outburst began on September 9 2024 with a RMS pulsed flux of 0.0579 +/- 0.009 keV cm^-2 s^-1 (12-25 keV) and is currently at 0.123 +/- 0.009 keV cm^-2 s^-1 (12-25 keV). Subtracting our current orbital model (see website below), the pulsed frequency on MJD 60582 is 107.7354 +/- 0.0001 mHz. 2S1553-54 is currently spinning up at about 1.2e-11 cycles/s^2 (0.09 cycles/day^2). The outburst was first reported by MAXI/GSE (ATel #16835, M. Nakajima et al.).
The GBM Accreting Pulsar Project.
