[AAVSO-HEN] GRB090217: Fermi-LAT Detection

[grb at aavso.org]

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TITLE:   GCN CIRCULAR
NUMBER:  8903
SUBJECT: GRB090217: Fermi-LAT Detection
DATE:    09/02/17 17:14:12 GMT
FROM:    Masanori Ohno at ISAS/JAXA  <ohno at astro.isas.jaxa.jp>

Masanori Ohno(ISAS/JAXA), Julie McEnery(NASA/GSFC),
and Veronique Pelassa(CNRS/IN2P3/LPTA) report
on behalf of the Fermi LAT team:

We report a detection by the Fermi Large Area Telescope of emission
from a GRB at 04:56:51 UT with detection significance of more than 5 sigma.
This burst is spatially and temporally correlated with a GBM detected
burst (trigger 256539404, GCN 8902).

This burst was found in a blind search in the LAT data,
and also independently by follow up studies around the GBM location.
The emission continues for up to 20 seconds after the GBM trigger,
 but commences several seconds after the GBM trigger.

The best LAT on-ground localization is found to be (RA,Dec=204.9, -8.4)
with a 90% containment radius of 0.52 deg (statistical; 68%
containment radius: 0.36 deg).

Further analysis is ongoing.

The Fermi LAT point of contact for this burst is
Masanori Ohno
(ohno at astro.isas.jaxa.jp)

The Fermi LAT is a pair conversion telescope designed to cover the
energy band from 20 MeV to greater than 300 GeV. It is the product of an
international collaboration between NASA and DOE in the U.S. and many
scientific institutions across France, Italy, Japan and Sweden.
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