TITLE:   GCN CIRCULAR
NUMBER:  41932
SUBJECT: GRB 250920B: Asiago optical observations
DATE:    25/09/21 17:57:22 GMT
FROM:    Daniele Bjørn Malesani at Cosmic Dawn Center, Niels Bohr Institute <daniele.malesani@nbi.ku.dk>

A. Reguitti (INAF/OAPd), L. Tomasella (INAF/OAPd), D. B. Malesani 
(DAWN/NBI and Radboud) report on behalf of a larger collaboration:

We observed the field of GRB 250920B (Gupta et al., GCN 41898; Sonawane 
& Meegan, GCN 41919) using the 67/92 Schmidt Telescope located at the 
Asiago observatory (Italy). Observations were carried out using a clear 
filter, which covers roughly the r and i bands.

The optical counterpart (Gupta et al., GCN 41898; Wu et al., GCN 41908; 
Hall et al., GCN 41914; Kuin & Gupta, GCN 41915) is well detected in our 
frames. At a mean epoch 2025 Sep 20.771 UT (9.74 hr after the GRB), we 
measure an AB magnitude r = 18.62 +- 0.06 (calibrated directly against 
r-band magnitudes from the Pan-STARRS catalog).

Considering the filter difference, our measurement is consistent with 
the nearly simultaneous observation by Hall et al. (GCN 41914).