Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 33611

IceCube-230405A: BOOTES-4/MET Optical Upper Limits
2023-04-14T15:57:24Z (a year ago)
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 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). 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 


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


The Burst Optical Observer and Transient Exploring System (BOOTES, 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.
Looking for U.S. government information and services? Visit