GCN Circular 37243
Subject
GRB 240821A: SVOM/VT follow-up and optical upper limit
Date
2024-08-23T09:58:45Z (9 months ago)
From
Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>
Via
Web form
SVOM/VT commissioning team: Y.L.Qiu, L.P.Xin, H.L.Li, 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)
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, GRB 240821A (Cangemi et al., GCN 37220; He et al. GCN 37226; Murphy et al., GCN 37232; Dalessi et al., GCN 37239) was observed by the SVOM/VT telescope started at 2024-08-22T11:34:02 UT (about 17 hours after the burst) in ToO mode. VT made the observations with two channels simultaneously, VT_B (400nm-650nm) and VT_R (650nm-1000nm). No new source was detected within the errorbox of EP-FXT sources (Turpin et al., GCN 37230) and Swift-XRT sources (Evans et al., 37236), down to the limit magnitude of about 23.0 mag in VT stacked images in both channels, compared to the DESI DR10 catalog.
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.
The SVOM/VT point of contact for this burst is: Liping Xin (xlp@nao.cas.cn)