Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 14674

GRB 130518A: Fermi GBM detection
2013-05-18T20:52:02Z (11 years ago)
Shaolin Xiong at UAH <>
Shaolin Xiong (UAH) reports on behalf of the Fermi GBM Team:

"At 13:54:37.53 UT on 18 May 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 130518A (trigger 390578080 / 130518580).

High peak flux from the GRB caused GBM to issue a repoint request,
but the spacecraft did not slew to this burst due to the Solar TOO.

The on-ground calculated location, using the GBM trigger
data, is RA = 355.88, DEC = 46.05 (J2000 degrees,
equivalent to 23 h 43 m, 46 d 03 '), with an uncertainty
of 1 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 43 degrees.

The GBM light curve consists of several pulses
with a duration (T90) of about 48 s (50-300 keV).
The time-averaged spectrum from T0+10 s to T0+60 s is
adequately fit by a Band function with Epeak = 396 +/- 9 keV,
alpha = -0.86 +/- 0.01, and beta = -2.27 +/- 0.04.

The event fluence (10-1000 keV) in this time interval is
(9.3 +/- 0.06)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+25.6 s in the 10-1000 keV band
is 45.4 +/- 0.4 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
Looking for U.S. government information and services? Visit