GCN Circular 37689
Subject
GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
Date
2024-10-03T09:38:25Z (4 months ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
N. Pankov (HSE, IKI), A. Moskvitin (SAO), E. Klunko (ISTP), V. Rumyantsev (CrAO), A. Pozanenko (IKI), I. Spiridonova (SAO), S. Belkin (HSE, IKI) report on behalf of IKI GRB FuN:
We observed the field of long GRB 240929A detected by INTEGRAL (Mereghetti et al., GCN 37630) and aslso detected by Fermi GBM (Fermi GBM team, GCN 37627; Preis et al., GCN 37629), SVOM (Zheng et al., GCN 37650), and GRBAlpha (Dafcikova et al., GCN 37657) with Zeiss-1000 1.0-meter telescope (equipped with EEV CCD42-40 and the Rc-filter) of SAO RAS observatory, AZT-33IK 1.5-meter telescope (equipped with ANDOR NEO CMOS camera and the R-filter) of Mondy observatory, and ZTSh 2.6-meter telescope (equipped with FLI ProLine PL4240 CCD and the R-filter) of CrAO. The observations began at SAO RAS on 2024-09-30 19:42:11 UT. Details of the observations are as follows:
Date UTstart t-T0 Exp. Filter UL Telesope
(mid, days) (n*s) (3sigma)
2024-09-29 22:46:17 0.138546 8*300 Rc 23.4 Zeiss-1000
2024-09-30 19:47:17 1.017543 28*120 R 22.0 AZT-33IK
2024-10-01 18:49:59 1.975663 50*120 R 24.0 ZTSh
Within the INTEGRAL localization circle (Mereghetti et al., GCN 37630) we found no variable sources. Additionally we found several sources which are absent in PS1 catalog but detected in the stacked image of initial Zeiss-1000 observations. All of the sources is barely visible in PS1 images. The table below shows the coordinates of the sources and the R mag obtained for the sources in these three epochs.
Source# RA(J2000) Dec(J2000) m(Sep.29) m(Sep.30) m(Oct.01)
1 00:09:34.87 +74:49:05.2 20.95±0.12 20.88±0.16 20.73±0.03
2 00:09:35.74 +74:48:55.1 21.83±0.16 >22 21.86±0.08
3 00:09:36.67 +74:50:37.0 21.45±0.15 21.58±0.20 21.51±0.06
4 00:09:36.70 +74:49:07.7 21.35±0.10 21.60±0.23 21.37±0.04
5 00:09:41.59 +74:48:24.1 21.00±0.11 20.70±0.15 20.66±0.03
6 00:09:41.98 +74:49:32.5 22.15±0.16 ~21.6 21.86±0.04
7 00:09:57.12 +74:50:11.0 21.73±0.12 ~21.7 21.78±0.07
8 00:09:58.78 +74:50:05.3 21.80±0.19 ~21.8 22.10±0.07
9 00:10:07.25 +74:50:21.8 21.80±0.15 ~21.8 22.08±0.07
10 00:10:08.93 +74:49:57.4 21.38±0.11 21.84±0.26 21.53±0.04
The magnitudes were calibrated against nearby USNO-B1.0 (R2) reference stars and are not corrected for the Galactic extinction. No variability was found among the sources. So we have no evident GRB240929A afterglow candidates, which is in agreement with previously reported observations (Lipunov et al., GCN 37628; Moretti & Pavoni, GCN 37642; Guidorzi et al., GCN 37672).