GRB 241213A: SVOM/VT optical candidate

The SVOM/VT conducted follow-up observations of the Swift-triggered GRB 241213A (Gupta et al., GCN 38547) in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously, from 10.636 hours to 15.7 hours after the burst. With the X band downlinked data, an uncatalogued optical source was detected within the errorbox of XRT (Osborne et al., GCN 38552) in VT_R stacked image, compared to the PanSTARRS catalog. The brightness of the source was estimated to be 23.8 ± 0.3 mag in AB magnitude in VT_R image at the mid time of 13.6 hours post the burst, with a total exposure time of 135*50 seconds. The source can not be detected in VT_B stacked image with 3 sigma upper limit of ~24.0 mag in AB magnitude. The source is located at RA, Dec = 116.17031, 35.27805, which is equivalent to: RA (J2000) : 07:44:40.87 Dec (J2000): +35:16:40.99 with an uncertainty of 0.5 arcsec. We proposed that this source is the candidate for the gamma-ray burst. Further follow-ups with SVOM/VT are scheduled to confirm the nature of the source. More deep follow-ups are encouraged. 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.