GCN Circular 37338
Subject
GRB 240825A: SVOM/VT optical detection
Date
2024-08-29T14:56:40Z (3 months ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
SVOM/VT commissioning team: Y. L.Qiu, L. P. Xin, H. L. Li, C. Wu, X. H. Han, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, L. Lan, W. J. Xie, X. M. Lu, R. S. Zhang, D. W. Xu, G. W. Li (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM) and P.Jesse (CEA).
SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), JeanLuc Attéia (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (UNLV)
report on behalf of the SVOM team:
During the commissioning phase of SVOM mission, we observed the field of the GRB 240825A (The Fermi GBM team,GCN 37273; Gupta et al., GCN 37274; Lalla et al., GCN 37288; Evans et al., 37290; Gropp et al., GCN 37294; Joshi et al., GCN 37298; Sharma et al., GCN 37301; Frederiks et al., GCN 37302; Wang and Xiong, GCN 37315) with SVOM/VT telescope started at 2024-08-26T18:16:41.50 UT (about 26.4 hours after the burst) in ToO mode. VT made the observations with two channels simultaneously, VT_B (400nm-650nm) and VT_R (650nm-1000nm). The optical afterglow (Gupta et al., GCN 37274; Jiang et al., GCN 37275; Dutton et al., GCN 37276; Odeh et al., GCN 37277, Zhang et al., GCN 37278; Li et al., GCN 37280, Izzo et al., GCN 37287; Lipunov et al., GCN 37289; Leonini et al., GCN 37291; Wu et al., GCN 37292; Martin-Carrillo et al., GCN 37293; Brivio et al., GCN 37295; Kuin et al., GCN 37296; Odeh et al., GCN 37299; Le Floc'h et al., GCN 37300; Guiffreda et al., GCN 37303, Zheng et al., GCN 37304, Wang et al., GCN 37306, Maksut et al., GCN 37307; Melandri et al., GCN 37310, Romanov, GCN 37335, Moskvitin et al., GCN37336) was detected in the VT stacked images, the magnitudes obtained by VT were: VT_B = 22.39 +/-0.2 mag, and VT_R = 21.12 +/-0.1 mag in AB magnitude.
More detailed analysis is ongoing.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT is an optical telescope on board SVOM with an aperture of 44 cm, designed to automatically follow the Eclairs triggers. It has two channels: VT_B and VT_R, covering wavelengths from 400 nm to 650 nm and 650 nm to 1000 nm, respectively. The two bands are observed simultaneously. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS.