TITLE:   GCN CIRCULAR
NUMBER:  38114
SUBJECT: GRB 241025A: LBT optical observations
DATE:    24/11/07 15:41:56 GMT
FROM:    Andrea Rossi at INAF <andrea.rossi@inaf.it>

A. Rossi, E. Maiorano (INAF/OAS), D. B. Malesani (DAWN/NBI and Radboud Univ.), A. Melandri, D. Paris, and E. Marini (INAF-OAR), report on behalf of a larger collaboration: 

We observed the optical counterpart of GRB 241025A  (Ambrosi et al., GCN 37859; Fermi GBM team, GCN 37860; Wang et al., GCN 37863; Li et al., GCN 37864) with the LBC camera mounted on LBT (Mt. Graham, AZ, USA) in the r', i', and z' bands with approximate midtime 04:54:00 UT on 2024-10-28, or 3.14 days after the burst. Observations were performed under an average seeing of ~1.2" but with a few passing cirrus.

The optical afterglow (Ambrosi et al., GCN 37859; Jiang et al., GCN 37862; Pereyra et al., GCN 37865; Xu et al., GCN 37866; SVOM/VT team, GCN 37871; Abdi et al., GCN 37882; Watson et al., GCN 37889; Mohan et al., GCN 37890; Vinko et al., GCN 37891; Gupta et al., GCN 37893; Pankov et al., GCN 37912; Moskvitin and Spiridonova, GCN 37914 and 37923; Klingler and Ambrosi, GCN 37919; Wang et al., GCN 37926) is well detected in all bands. We measure a preliminary AB magnitude of  

r' = 23.6+-0.1,

calibrated against Pan-STARRS field stars, and not corrected for the foreground Galactic extinction.

We acknowledge excellent support from the LBTO and LBT-INAF staff, particularly O. Kuhn and R. Ansaldi.