Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. See news and announcements

GCN Circular 42897

Subject
GRB 251129A / EP251129a: SAO RAS optical observations
Date
2025-11-29T17:59:49Z (14 hours ago)
From
Alexander Moskvitin at SAO RAS <mosk@sao.ru>
Via
Web form
A. S. Moskvitin and O. I. Spiridonova (SAO RAS) 
report on behalf of GRB follow-up team.

We observed the field of the SVOM GRB 251129A (Tan et al., GCN 42877)
also detected by Einstein Probe as EP251129a (Wu et al., GCN 42884)
and Swift (Evans, GCN 42888; Page et al., GCN 42891) 
with the Zeiss-1000 1m telescope of the SAO RAS on November 29, 
15:27:01--16:00:22 UT (t_mid - T0 = 0.54973 days). We obtained 
6 * 300 sec images in Rc band.

The optical afterglow (Angulo et al., GCN 42880; Wu et al., GCN 42882; 
Watson, GCN 42883; Masi, GCN 42885; Li et al., GCN 42887; 
Lipunov et al., GCN 42892) is clearly detected in the stacked frame 
with the following brightness.

Date        UT start  t-T0       Exp.    Filter  OT     Err.  UL      
                     (mid,days)  (n*s)                       (3sigma)

2025-11-29  15:27:01  0.54973    6*300   Rc      21.00  0.07  22.8

This preliminary photometry is based on nearby stars from the USNO-B1 
catalogue (R2 magnitudes) and is not corrected for the Galactic 
extinction.
Looking for U.S. government information and services? Visit USA.gov