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GCN Circular 33727

GRB 230506B: Swift detection of a burst
2023-05-06T13:28:17Z (a year ago)
K.L. Page at U Leicester <>
S. Dichiara (PSU), C. Gronwall (PSU), J. A. Kennea (PSU), A. Y. Lien (U
Tampa), K. L. Page (U Leicester), B. Sbarufatti (INAF-OAB) and M. A.
Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory

At 12:45:18 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 230506B (trigger=1167266).  Swift slewed immediately to the
The BAT on-board calculated location is
RA, Dec 326.993, +44.540 which is
   RA(J2000) = 21h 47m 58.32s
   Dec(J2000) = +44d 32' 24.00"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty).  No BAT light-curve is available at this time.

The XRT began observing the field at 12:47:12 UT, 114 seconds after
the BAT trigger. Using promptly downlinked data we find an
uncatalogued X-ray source with an enhanced position: RA, Dec 326.97876,
44.51108 which is equivalent to:
   RA(J2000)  = 21h 47m 54.90s
   Dec(J2000) = +44d 30' 39.9"
with an uncertainty of 6 arcseconds (radius, 90% containment). This
location is 110 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at

UVOT prompt data are not available at this time.  We are waiting for
the full dataset to search for an UVOT counterpart.

Due to a communications issue, no realtime alerts were received for this
GRB. Therefore, results in this GCN are based on rapidly reported results,
and will be refined in a future GCN Circular.

Burst Advocate for this burst is S. Dichiara (sbd5667 AT
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information:

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