TITLE: GCN CIRCULAR NUMBER: 33124 SUBJECT: IceCube-221229A: BOOTES-2/TELMA Optical Upper Limit DATE: 22/12/30 15:32:21 GMT FROM: Dingrong Xiong at Yunnan Observatories of CAS, China D. R. Xiong, J. M. Bai, Y. F. Fan, K. Ye, C. J. Wang, Y. X. Xin, B. L. Lun, J. R. Mao, X. H. Zhao, L. Xu, X. G. Yu, K. X. Lu, X. Ding, D. Q. Wang (Yunnan Observatories), A. J. Castro-Tirado, E. Fernandez-Garcia, Y. D. Hu (IAA-CSIC) and C. J. Perez del Pulgar (UMA) on behalf of the BOOTES team report: On 2022-12-29 at 07:25:27.88 UT IceCube detected a track-like event with a high probability of being of astrophysical origin (GCN 33122). We observed the best-fit position of IceCube-221229A with BOOTES-2/TELMA 0.6m automatic optical telescope. The magnitude was calculated using three bright stars in the same frame and the SDSS DR16 catalogue as reference. We did not detect any optical source within the best-fit position. The upper limit of magnitude (without being corrected for Galactic extinction) is given as follows. Tmid-T0 (day) | UT (start) | Upper Limit (error) | Exposure Time | Filter | Comment -------------------------------------------------------------------------------------------------------------- 0.61 | 22-12-29T22:05:40.929 | 19.22 (0.11) | 5*300s (co-added) | Clear | Strong moonlight --------------------------------------------------------------------------------------------------------------- The Burst Optical Observer and Transient Exploring System (BOOTES) is a world-wide automatic telescope network which aims to repaid follow-up of transient and astrophysical sources in the sky for which the first station was installed in 1998 (Hu et al. 2021). The BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain). We acknowledge the support of these staffs from the BOOTES telescope networks.