GCN Circular 42127
Subject
GRB 251005C: VLT/X-shooter Imaging
Event
Date
2025-10-06T18:04:22Z (2 days ago)
Edited On
2025-10-06T20:15:26Z (2 days ago)
From
Massine El Kabir <m.elkabir@campus.unimib.it>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Massine El Kabir <m.elkabir@campus.unimib.it>
Via
Web form
GRB 251005C: VLT/X-shooter Imaging
Muskan Yadav (U Rome), Yu-Han Yang (U Rome), Massine El Kabir (U Rome), Niccolò Passaleva (U Rome), Eleonora Troja (U Rome) report on behalf of the ERC BHianca team:
We observed the field of GRB 251005C (K. L. Page et al., GCN 42113) with the Xshooter spectrograph on the ESO VLT UT3 (Melipal). Observations began at T+16.5 hours. We obtained a total exposure of 335 s using the acquisition and guiding (A&G) camera. Observations were carried out in the i’ filter at an average airmass of about 1.4 and seeing 0.75 arcsec.
Within the XRT error region (Goad et al., GCN 42116) we detect a faint (i~24 AB mag) source at coordinates RA, Dec (J2000) = 05:02:44.03, +16:52:51.632. The object appears extended in our images.
We also detect the SVOM/VT optical candidate (J. T. Palmeiro et al., GCN 42123) at a significantly fainter magnitude (i~24 AB mag), confirming its rapid fading. We thus suggest that this is the GRB optical counterpart.
We thank the staff at the VLT, for the rapid execution of these observations.