TITLE:   GCN CIRCULAR
NUMBER:  37951
SUBJECT: EP241021a: SAO RAS observations of rebrightening
DATE:    24/10/30 00:33:38 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin and O. I. Spiridonova (SAO RAS), report
on behalf of the GRB follow-up team.

We observed the field of X-ray transient EP241021a (Hu et al.,
GCN 37834) with the 1-m telescope of SAO RAS, Zeiss-1000
equipped with the CCD-photometer on October 28 and 29.

We detect the OT (Fu et al., GCNs 37840, 37842; Li et al.,
GCNs 37844, 37846; Ror et al., GCN 37845; Zheng et al., GCN 37849;
Moskvitin & Spiridonova, GCN 37850; Pugliese et al., GCN 37852;
Pérez-Fournon et al., GCN 37858; Bochenek & Perley, GCN 37869;
Kumar et al., GCN 37875; Busmann et al., GCN 37877; J-Jin et al.,
GCN 37892; Freeburn et al., GCNs 37911, 37942; Quirola-Vasquez et al.,
GCN 37930) in rebrightening state with the following results.

date    UT_start--UT_end   t_mid-T0  exp, s   R magnitude     R_lim
Oct. 28 19:41:42--23:00:33 7.6758    15 x 300 21.57 +/- 0.08  23.0
Oct. 29 19:55:32--21:03:35 8.6400    12 x 300 21.64 +/- 0.05  23.6

Preliminary photometry was performed in the aperture with r = 2".5,
calibrated against nearby SDSS stars (magnitudes converted with
Lupton 2005 equations) and not corrected for the Galactic extinction.