GCN Circular 42399
Subject
GRB 251013C: further SAO RAS optical observations
Event
Date
2025-10-23T14:44:06Z (a year ago)
From
Alexander Moskvitin at SAO RAS <mosk@sao.ru>
Via
Web form
A. S. Moskvitin, O. I. Spiridonova, V. V. Vlasyuk (SAO RAS)
report on behalf of GRB follow-up collaboration.
We observed the field of the GRB 251013C (The Fermi GBM team,
GCN 42221; Rakotondrainibe et al., GCN 42222) with the 1-m SAO RAS
telescope Zeiss-1000 equipped with the CCD-photometer
on October 20 and 21 nights.
The optical afterglow (Palmerio et al., GCN 42223;
Perez-Garcia et al., GCN 42225; Konno et al., GCN 42226;
Martin-Carrillo et al., GCN 42227; Masi, GCN 42228; Palmerio et al.,
GCN 42229; Moskvitin et al., GCN 42230; Gompertz et al., GCN 42231;
Lipunov et al., GCN 42235; Garnavich, GCN 42240; Watson et al.,
GCN 42241; López-Cámara et al., GCN 42242; Brosio et al., GCN 42251;
Reguitti, GCN 42253; Quintana-Ansaldo et al., GCN 42254;
Maksut et al., GCN 42256; Ghosh et al., GCN 42261; Quadri et al.,
GCN 42262; Adami et al., GCNs 42266, 42276, 42338; Peretto et al.,
GCN 42267; Ruocco et al., GCN 42269; Calapai, GCN 42275;
Globus et al., GCN 42279; Evans, GCN 42281; Abidkhanov et al.,
GCN 42283; Siegel, GCN 42298; Leonini et al, GCN 42301; Méndez et al.,
GCN 42318; He et al., GCN 42319; Pavoni et al., GCN 42333; Bochenek
and Perley, GCN 42334; Volnova et al., GCN 42396) is clearly detected
in the stacked images with the following brightness.
Date UT start t-T0 Exp. Filter OT Err. UL
(mid, d) (s)
2025.10.20 19:59:38 7.12682 13 x 300 Rc 21.61 +/- 0.11 22.7
2025.10.21 17:02:31 8.01103 19 x 300 Rc 21.80 +/- 0.10 23.0
Preliminary photometry is based on the nearby SDSS objects
(magnitudes converted with Lupton 2005 equations)
and has not corrected for the Galactic extinction.