Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. See news and announcements

GCN Circular 22958

Subject
Swift Trigger 848621 is not an astrophysical event
Date
2018-07-18T22:09:09Z (7 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
J.D. Gropp (PSU), J. A. Kennea (PSU), D. M. Palmer (LANL),
B. Sbarufatti (PSU) and A. Tohuvavohu (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 21:54:34 UT, the Swift Burst Alert Telescope (BAT) found a 
marginal-significance peak in an untriggered image near the
line of site to a nearby galaxy (trigger=848621).  
Swift did not slew to the location due to an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 190.395, +11.798 which is 
   RA(J2000) = 12h 41m 35s
   Dec(J2000) = +11d 47' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is typical for an image trigger,
no variation is apparent in the BAT lightcurve. 

BAT alerted due to a program of following up marginal detections
in the vicinity of nearby galaxies.  In this case, the low significance
of the image peak (5.86 sigma), the lack of a rate trigger, and the 
distance between the peak and the putative host galaxy (9 arcmin),
implies that this is merely a noise peak in image space and
not an astrophysical event. 

No further observations are planned.
Looking for U.S. government information and services? Visit USA.gov