Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 9600

GRB 090701: Fermi GBM detection
2009-07-01T15:43:49Z (15 years ago)
Sheila McBreen at MPE <>
Sheila McBreen (UCD/MPE)
reports on behalf of the Fermi GBM Team:

"At 05:23:55.84 UT on 01 July 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090701 (trigger 268118637 / 090701225).

The on-ground calculated location, using the GBM trigger
data, is RA = 114.7, DEC = -42.1 (J2000 degrees,
equivalent to 07 h 39 m, -42 d 06 '), with an uncertainty
of 4.2 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 13 degrees.

The GBM light curve comprises one pulse
with a duration (T90) of about 12 s (8-1000 keV).
The time-averaged spectrum from T0-10 s to T0+2 s is
adequately fit by  a simple power law function
with index 1.84 +/- 0.09 (chi squared 440 for 485 d.o.f.).

The event fluence (8-1000 keV) in this time interval is about
4.5E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.024 s in the 8-1000 keV band
is 2.1 +/- 0.1 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