GCN Circular 39596
Subject
EP250302a: Optical Observations at CrAO and SAO RAS
Event
Date
2025-03-05T12:52:41Z (5 months ago)
Edited On
2025-03-06T14:38:56Z (4 months ago)
From
Nicolai Pankov at HSE, IKI RAS <colinsergesen@gmail.com>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Nicolai Pankov at HSE, IKI RAS <colinsergesen@gmail.com>
Via
Web form
N. Pankov (HSE, IKI), A. Moskvitin (SAO RAS), O. I. Spiridonova (SAO RAS), A. Pozanenko (IKI), V. Rumyantsev (CrAO), E. Klunko (ISTP) report on behalf of IKI-GRB-FuN:
We performed optical observations of the field of a fast X-Ray transient EP250302a (Dai et al., GCN 39556; Page et al., GCN 39557) in the R filter with the 2.6-meter telescope of the Crimean Astrophysical Observatory (CrAO) and the 1-meter Zeiss-1000 telescope of the Special Astrophysical Observatory of the RAS (SAO RAS). The observations began on 2025-03-03 (UT) 01:51:40, i.e. 1.42750 days since trigger. The optical source (Zhu et al., GCN 39550; Busmann et al., GCN 39551; Leonini et al., GCN 39553; Wu et al., GCN 39555; Xin et al., GCN 39558; Adami et al., GCN 39560; Yang et al., GCN 39561; Becerra et al., GCN 39562; Izzo et al., GCN 39564; Pankov et al., GCN 39565; Reguitti, GCN 39568; Komesh et al., GCN 39569; Shilling and Breeveld, GCN 39570; Aryan et al., GCN 39572; Moskvitin et. al, GCN 39576; Wu et. al, GCN 39578; Pankov et. al, GCN 39586; Gupta et. al, GCN 39593) is not detected in the stacked images from both telescopes. The preliminary upper limits are as follows:
Date UT start t-T0 Exptime Filter UL Telescope
(mid, days) (s) (3sigma)
2025-03-03 01:51:40 1.44460 9*300 Rc 22.7 Zeiss-1000/SAO RAS
2025-03-04 23:21:23 2.33286 14*120 R 23.3 ZTSh/CrAO
The photometry is based on nearby stars from the USNO-B1.0 catalog (R2 magnitudes) and has not been corrected for the Galactic extinction.