GCN Circular 44654
Subject
GRB 260516D: SVOM/VT optical bright candidate
Event
Date
2026-05-17T01:27:37Z (11 days ago)
Edited On
2026-05-18T13:04:27Z (10 days ago)
From
Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Via
Web form
H. L. Li, L. P. Xin, Y. N. Ma, C. Wu, Z. H. Yao, Y. L. Qiu, X. H. Han, J. Wang, Y. Xu, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, L. Lan, J. R. Xu, J. S. Deng, J. Y. Wei (NAOC), J. Palmerio and A. Saccardi (CEA/Irfu) report on behalf of the SVOM/VT team.
SVOM/VT performed ToO observation to the field of GRB 260516D detected by SVOM/ECLAIRs (sb26051616, Brunet et al., GCN 44649). The observation started at 2026-05-16T22:20:51 UTC, 1.69 hour post trigger in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously.
An uncatalogued optical source was clearly detected in single frames of both channels within the errobox of SVOM/ECLAIRs (Brunet et al., GCN 44649), compared to the Legacy Survey. The position is at R.A., Dec. = 233.827956, 6.529103 degrees, equivalent to:
R.A. (J2000) = 15:35:18.71
Dec. (J2000) = +6:31:44.77
with an uncertainty of 0.5 arcsec.
The measurements in AB magnitudes are given below:
Mid_time Band Exposure Time Magnitude (AB)
1.71 hour VT_B 70 sec 19.62 +/- 0.05 mag
1.69 hour VT_R 70 sec 19.00 +/- 0.05 mag
Our photometry was not corrected for Galactic extinction.
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.