GCN Circular 33611

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 2023-04-05 at 13:20:20.04 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin (GCN 33567
Not found
 
 
). We observed the nearest gamma-ray source 4FGL J0802.0+1006 and the best-fit position of IceCube-230405A with BOOTES-4/MET robotic telescope.The magnitudes were calculated using bright stars in the same frame and the SDSS-DR16 as reference. We did not detect any optical source within the best-fit position, and also the optical counterparts of 4FGL J0802.0+1006. The upper limits of magnitudes (without being corrected for Galactic extinction) are given as follows. 

Sources | Tmid-T0 (day) | UT (start) | Upper Limit (error) | Exposure Time | Filter 

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Best-fit position| 1.18 | 23-04-06 17:43:37.49 | 18.96 (0.06) | 300s | SDSS-i  

J0802.0+1006 | 1.2 | 23-04-06 18:08:52.38 | 18.69 (0.04) | 300s | SDSS-i

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The Burst Optical Observer and Transient Exploring System (BOOTES, bootes.iaa.es) is a completed world-wide network of robotic telescopes led at IAA-CSIC (Spain) which aims at following-up transients and other astrophysical sources in the sky for which the first station was installed in 1998 (Castro-Tirado et al. 1999). The fourth station of the BOOTES Network, BOOTES-4/MET, is located at the Lijiang Observatory of the Yunnan Observatories of China (Xiong et al. 2020). See also Hu et al. (2021). We acknowledge the support of BOOTES-4 technical staffs.