GCN Circular 39658
Subject
GRB 250309B / AT2025dws: further SAO RAS optical observations
Event
Date
2025-03-10T23:50:28Z (10 months ago)
From
Alexander Moskvitin at SAO RAS <mosk@sao.ru>
Via
Web form
A. S. Moskvitin, O. I. Spiridonova (SAO RAS), A. S. Pozanenko (IKI),
A. Ghosh, S. Razzaque (CAPP, University of Johannesburg),
Yu. V. Sotnikova (SAO RAS) report on behalf of a larger collaboration.
We observed the field of GRB 250309B / AT2025dws (Preis and Greiner,
GCN 39629; Fermi GBM team, GCN 39635; McDermott et al., GCN 39642;
Wang et al., GCN 39648; Page and Evans, GCN 39649; Kozyrev et al.,
GCN 39652; Frederiks et al., GCN 39655; Scotton, GCN 39657)
with Zeiss-1000 1-m telescope of SAO RAS, equipped
with the CCD-photometer. We obtained 19 x 300 sec. images in Rc band
on March 10, 21:37:13 -- 23:23:40 UT (t_mid - T0 = 1.6194 days).
The optical candidate ZTF25aaitvjt / AT2025dws (Stein et al.,
GCN 39639; Pérez-Fournon et al., GCN 39643; Stein and Ahumada,
GCN 39644; Moskvitin et al., GCN 39645; Perley et al., GCN 39646;
Malesani et al., GCN 39647; Ducoin et al., GCN 39650; Shin et al,
GCN 39654) is clearly detected in the stacked image
with the brightness of R = 20.65 +/- 0.13.
We do not performed host galaxy subtraction.
The photometry is based on nearby stars from the USNO-B1.0 catalog
(R2 magnitudes) and has not been corrected for the Galactic extinction.