GCN Circular 43258
Subject
GRB 251230A/EP#01709250693 (likely EP251230a): FTW optical and NIR observations
Event
Date
2025-12-30T02:22:30Z (2 days ago)
From
Malte Busmann at Ludwig-Maximilians-Universität München <m.busmann@physik.lmu.de>
Via
Web form
Malte Busmann (LMU), Xander J. Hall (CMU), Brendan O'Connor (CMU), Daniel Gruen (LMU), and Antonella Palmese (CMU) report:
We observed the counterpart of Swift GRB 251230A (Lanava et al. GCN 43252, Li et al. GCN 43255) which is spacially and temporally consistent with EP trigger 01709250693 (likely EP251230a) with the Three Channel Imager (3KK) at the Fraunhofer Telescope at Wendelstein Observatory (FTW) in the r, i, and J-band simultaneously for 2 x 180 s starting at 2025-12-30T01:50:41 UT (28.3 minutes after the trigger). We detect the counterpart in all bands and measure an r-band magnitude of
r = 16.30 +/- 0.05 AB mag.
The magnitude is calibrated against the PS1 catalog and not corrected for Galactic extinction.
We thank Christoph Ries from the Wendelstein Observatory for the rapid response in obtaining these observations.