TITLE:   GCN CIRCULAR
NUMBER:  38328
SUBJECT: LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
DATE:    24/11/26 16:22:50 GMT
FROM:    Dong Xu at NAOC/CAS <dxu@nao.cas.cn>

S.Q. Jiang, X. Liu, S.Y. Fu, J. An, Z.P. Zhu, D. Xu (NAOC) report on behalf of a large collaboration:

We observed the field of the Swift/BAT-GUANO candidate counterpart (DeLaunay et al., GCN 38308) of the LIGO/Virgo/KAGRA gravitational wave event S241125n (LIGO/Virgo/KAGRA, GCN 38305; GCN 38309; GCN 38312; GCN 38313) using the GOT-0.5m telescope located at Gaoyazi, Xinjiang, China. Observations started at 18:49:17 UT on 2024-11-25, i.e., 17.796 hr after the S241125n trigger, and we obtained 32 x 180 s frames in the Sloan r filter.

No new optical source is detected in our stacked image within the Swift/BAT-GUANO 5 arcmin 50% containment area via cross-match with the PanSTARRS catalog, down to the 5-sigma limiting magnitude of r > 20.6, calibrated with nearby PanSTARRS stars and not corrected for Galactic extinction.

We acknowledge the excellent support from L.F. Huo and M.M. Yang for enabling these observations.