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GCN Circular 33102

IceCube-221224A: BOOTES-4/MET Optical Upper Limit
2022-12-25T16:31:57Z (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 22-12-24 at 00:55:09.3 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The nearest gamma-ray source 4FGL J2223.3+0102 is 0.39 deg away from the best-fit event position, but without localization of 90% uncertainty region of the event (GCN 33097).

We observed the best-fit position of IceCube-221224A and the gamma-ray source 4FGL J2223.3+0102 with BOOTES-4/MET 0.6m automatic optical telescope. We did not detect any optical source within localizations of both them. The upper limits of magnitudes (without being corrected for Galactic extinction) are given as follows. 

Name | UT (start) | Upper Limits (3-sigma) | Exposure Time | Filter 


Best-fit position ofIceCube-221224A | 22-12-24T11:36:39.25 | 18.90 (0.05) | 5*60s | Clear 

4FGL J2223.3+0102| 2022-11-24T12:06:12.63 | 18.20 (0.04) | 10*60s | SDSS-i  


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 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). We acknowledge the support of these staffs from the BOOTES telescope networks.
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