GCN Circular 37016
Subject
EP240801a: optical observations at CrAO and AbAO
Date
2024-08-02T15:06:19Z (4 months ago)
From
Alexei Pozanenko at IKI, Moscow <grb.alex@gmail.com>
Via
legacy email
N. Pankov (HSE, IKI), A. Pozanenko (IKI), V. Rumyantsev (CrAO),R. Ya.
Inasaridze (AbAO) report on behalf of GRB-IKI-FuN:
We observed the field of EP240801a (Zhou et al, GCN 36997) with ZTSh 2.6 m
telescope of CrAO, and AS-32 0.7 m telescope of AbAO. The observations were
carried out in moderate conditions with seeing of about 2.0 arcsec. We took
a series of images in the R-filter, starting on 2024-08-01 20:28 (UT) at
CrAO (i.e. 11 hours after the EP trigger). We clearly detect the optical
counterpart (Fu et al, GCN 36998; Li et al, GCN 36999; Zheng et al, GCN
37000; Aryan et al, GCN 37002; An et al, GCN 37004; Pérez-Fournon et al,
GCN 37007; Malesani et al, GCN 37008; Zhu et al, GCN 37010; Moskvitin &
Spiridonova, GCN 37012; Quirola-Vásquez et al, GCN 37013; Moretti et al.,
GCN 37014; Turpin et al., GCN 37015) in images from CrAO, while obtaining
upper limit at AbAO. Preliminary photometry is given below:
Date UT start t-T0 Exp. Filter OT Err. UL(3 sigma) Scope
(mid, days) (s)
2024-08-01 20:28:07 0.50492 15x120 R 21.3 0.1 23.7 ZTSh
2024-08-01 20:32:01 0.50970 44x60 R n/d n/d 21.0 AS-32
The magnitudes were calibrated using nearby stars from USNO-B1.0
catalog (R2 mags) and are not corrected for the Galactic extinction
A(R) = 0.237 mag (S&F 2011) towards the EP source. The obtained results are
consistent with observations published earlier.