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2S 1417-624 in Outburst

ATEL # 2275; Elif Beklen (METU) and Mark H. Finger (USRA) for the GBM Pulsar Project Team
on 30 Oct 2009; 18:48 UT
Distributed as an Instant Email Notice (Transients)
Password Certification: Dr. Mark H. Finger (

Subjects: X-ray, Gamma Ray, Binaries, Neutron Stars, Pulsars, Transients
Referred to by ATEL #: 2276

Observations with the GBM on Fermi show that the transient Be/X-ray binary pulsar 2S 1417-624 is currently in outburst. Coherent pulsations from the source at a 17.5 s period have been detected in the GBM data since October 18. The rms pulsed flux has been increasing, reaching 12 mCrab (12-52 keV) during October 28-29. From October 24.0 to 30.0 the spin frequency (corrected using the binary orbital elements of Inam et al. 2004) increased at a rate of (8.5 +/- 1.0) x 10E-12 Hz/s, reaching 57.09623(14) mHz on October 29.0 (MJD 55133.0).

The Swift/BAT monitoring shows a flux of 40 mCrab on October 29 and 90 mCrab on October 30. The last reported detection of this source was made with INTEGRAL in 2008 July (ATel# 1613).

GBM Pulsar Project

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