[vsnet-grb-info 23451] Title: GRB 190828B: VLT/X-shooter optical afterglow candidate

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25550
SUBJECT: Title: GRB 190828B: VLT/X-shooter optical afterglow candidate
DATE:    19/08/29 16:58:17 GMT
FROM:    Kasper Elm Heintz at Univ. of Iceland and DAWN/NBI  <keh14 at hi.is>

J. P. U. Fynbo (DAWN/NBI), K. E. Heintz (Univ. of Iceland), D. B. Malesani (DTU space), and D. A. Perley (LJMU), report on behalf of the Stargate collaboration:

We imaged the field of the Swift (Dichiara et al., GCN 25517) and Fermi-GBM (Roberts et al., GCN 25536) detected GRB 190828B with the ESO-VLT/X-shooter acquisition camera between 00:03:44 and 00:22:49 UT on August 29 (i.e. 11.15 hr after the trigger). From the combined images, obtained with a total integration time of 210 sec, we identify a faint source within the XRT error circle with magnitude r = 23.55 +/- 0.15 AB mag, calibrated from the photometry of nearby field stars as listed in the Pan-STARRS archival data. To verify whether this source is the afterglow or host galaxy of the GRB, a second epoch of images is required.

We acknowledge the ESO observing staff at Paranal, especially Alain Smette, Camila Navarrete and Linda Schmidtobreick.