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GCN Circular 33270

Subject
IceCube-230201A: BOOTES-4/MET Optical Upper Limits
Date
2023-02-05T07:57:38Z (2 years ago)
From
Dingrong Xiong at Yunnan Observatories of CAS, China <xiongdingrong@ynao.ac.cn>
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 2023-02-01 at 06:20:54.42 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. Three gamma-ray sources (4FGL J2256.7+1307, 4FGL J2308.9+1111 and 4FGL J2252.6+1245) listed in the 4FGL Fermi-LAT catalog are located within the 90% containment region (GCN 33244Not found
 
 
, 33248Not found
 
 
).  

We observed the three gamma-ray sources and the best-fit position of IceCube-230201A with BOOTES-4/MET robotic telescope.The magnitude was calculated using bright stars in the same frame and the Pan-STARRS catalogue as reference. We did not detect any optical source within the best-fit position, and also the optical counterparts of the three gamma-ray sources

The upper limits of magnitudes (without being corrected for Galactic extinction) are given as follows. 

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

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Best-fit position| 2.274 | 23-02-03 12:55:15.82 | 19.3 (0.07) | 6*300s (co-added) | Clear  

J2256.7+1307 | 1.236 | 23-02-02 12:00:06.45 | 17.67 (0.16) | 2*300s (co-added) | Clear 

J2308.9+1111| 1.273 | 23-02-02 12:53:51.65 | 19.748 (0.04) | 2*300s (co-added) | Clear 

J2252.6+1245 | 1.286 | 23-02-02 13:13:22.89 | 19.06 (0.06) | 2*300s (co-added) | Clear 

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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.