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GCN Circular 25284

Alert from the HAWC Burst Monitor
2019-08-07T21:14:38Z (5 years ago)
Hugo Ayala at Pennsylvania State University <>
The HAWC Collaboration  (

On August 6, 2019, at 13:20:48.00 UT, HAWC detected a burst signal from its
GRB Monitoring.
This monitor system looks for excesses above the expected background in
time windows of 0.2, 1, 10 and 100 seconds.
This event was found in the 100-second time window starting at the reported
trigger time.

The monitor system found that this alert has a false alarm rate of 0.83
event(s) per year.
The position of the alert is (RA, Dec) = (78.125 deg, +6.589 deg) J2000
with a 90% containment radius of 0.4 deg (statistical only).

The initial automated alert is recorded here:

We strongly encourage follow-up observations of the HAWC alert region.

HAWC is a very-high-energy gamma-ray observatory operating in Central
Mexico at latitude 19 deg. north.
Operating day and night with over 95% duty cycle, HAWC has an instantaneous
field of view of 2 sr and surveys 2/3 of the sky every day.
It is sensitive to gamma rays from 300 GeV to 100 TeV.
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