GRB 230628A

The Fermi GBM team reports the detection of a likely SHORT GRB

"At 05:35:36.16 UT on 28 June 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230628A (trigger 709623341/230628233).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 139.19, Dec = -11.54 (J2000 degrees, equivalent to J2000 9h 16m, -11d 32'),
with a statistical uncertainty of 16.84 degrees.

The angle from the Fermi LAT boresight is 51 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628233/quicklook/glg_skymap_all_bn230628233.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628233/quicklook/glg_healpix_all_bn230628233.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628233/quicklook/glg_lc_medres34_bn230628233.gif"

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3999 s of XRT Photon Counting mode data and 9 UVOT
images for GRB 230628A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 171.84876, -11.46370 which is equivalent
to:

RA (J2000): 11h 27m 23.70s
Dec (J2000): -11d 27' 49.3"

with an uncertainty of 2.1 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.