GCN Circular 2584

S. Golenetskii, E. Mazets, V. Pal'shin, and D. Frederiks on behalf
of Konus-Wind and Helicon/Coronas-F teams,

T. Cline, on behalf of the Konus GRB team,

A weak GRB 040427b was detected by Konus-Wind at 20:12:36.251 UT
and Helicon-Coronas-F at 20:12:36.871 UT.
It had a duration of approximately 12s.

In addition, 76.5 s after the GRB a short intense soft X-ray burst of
different origin was detected by both instruments. It had a duration
~0.19s, fluence 7x10-7 erg/cm2 and peak flux 6x10-6 erg/(cm2 s),
both in 20-100 keV range. Its spectrum can be fitted by power law with
approximate photon index -4.
The X-Ray burst source is located near ecliptic plane
(+/- 15 deg, according to Konus-Wind data) and in anti-solar hemisphere
(according to Helicon data).

[GCN OPS NOTE:  This Circular was delayed 3 days due to a problem
caused by a recent security-tightening measure implimented by GSFC
network operations.  This affects only the Circulars -- the Notices
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to be solved soon (Tuesday 04May04), Circular submission can still
be processed, albeit manually, if you CC scott@milkyway.gsfc.nasa.gov.
My apologies for the inconvenience.]