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GCN Circular 22706

Swift trigger 831888: misidentification of 4U 1416-62
2018-05-11T18:59:18Z (6 years ago)
Amy Lien at GSFC <>
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), 
B. Sbarufatti (PSU), and A. Tohuvavohu (PSU) 
report on behalf of the Swift Team:

Further ground analysis shows that the BAT trigger #831888 
(Tohuvavohu et al. GCN Circ. 22699) was due to misidentification
of 4U 1416-62 (a.k.a. 2S 1417-624 and H 1417-624). 
The misidentification was caused by a known race condition in the 
Swift/BAT software, which leads to incorrect spacecraft attitude 
information to be applied to a known source.

4U 1416-62 is currently undergoing a giant outburst, which is detected 
by MAXI (Nakajima et al. ATel #11479) and the BAT transient monitor
(Krimm et al. ATel #11569).

The known X-ray source 1RXS J141805.9-621902, detected in the 
XRT field of view at a flux level of 1.41+/-0.2 E-12 erg/cm^2/s, is 
unrelated to BAT the trigger.

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