GCN Circular 39923
Subject
GRB 250328A: SVOM/VT optical observation
Event
Date
2025-03-29T12:50:45Z (3 months ago)
From
Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Via
Web form
H. L. Li, L.P. Xin, Y. L. Qiu, C. Wu, J. Wang, W.J. Xie, Z. H. Yao, Y. Xu, P. P. Zhang, X. H. Han, Y. J. Xiao, H. B. Cai, J. Y. Wei (NAOC)，M. Brunet, J. Malzac (IRAP) report on behalf of the SVOM team:
SVOM performed a ToO observation on the burst triggered by SVOM/ECLAIRs (Brunet et al., GCN 39910). SVOM/VT began observing the field from about 2 hours to 7 hours after the burst in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously.
With X band downlinked data, the candidate reported (Schneider et al., GCN 39919, Schneider et al., GCN 39920) was clearly detected in stack images in both channels. The magnitudes are: VT_R=21.7+/- 0.1 mag(AB) and VT_B=22.0+/0.1 mag(AB) with the mid time of 4.85 hours after the burst. The photometry has not been corrected for the Galactic extinction. No any significant fading with larger than 0.2 mag during our observations was found.
Further observations are 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 was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS.