GRB 241029A: Mephisto observations

The 1.6m Multi-channel Photometric Survey Telescope (Mephisto) of Yunnan University located at Lijiang Observatory was triggered to observe the field of GRB 241029A detected by Fermi/GBM (Fermi GBM team, GCN 37932), SVOM/ECLAIRs and SVOM/GRM (Schanne et al., GCN 37934; Wang et al., GCN 37935). Several uvgriz-band images were acquired starting from 11:47:29 2024-10-29 UT. We clearly detect the uncatalogued source reported by Jiang et al. (GCN 37937) in 300s of r band images and the preliminary estimated magnitude is 20.47+- 0.11 (r-band, 12:19:27 2024-10-29 UT). Further analysis is in progress. -------------------------------------------------------------------------- Mephisto (Multi-channel Photometric Survey Telescope) is a 1.6m wide-field multi-channel telescope, the first of its type in the world, capable of imaging the same field of view in three optical bands simultaneously. It provides real-time, high-quality colors of stellar objects. The on-site telescope assemblage and commissioning were carried out in September 2022. The first light in all three channels was achieved on 2023 December 21. --------------------------------------------------------------------------