TITLE:   GCN CIRCULAR
NUMBER:  32989
SUBJECT: IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
DATE:    22/11/28 12:34:52 GMT
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, 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:<p>

 

On 2022-11-24 at 15:46:02.26 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin (GCN 32980). The gamma-ray source 4FGL J1956.1+0234 (RA=299.04 deg, Dec=2.57 deg, J2000) is located in the 90% uncertainty contour, and 1.16 deg away from the best fit position (GCN 32980, 32983). <p>

 

We observed the gamma-ray source 4FGL J1956.1+0234 with BOOTES-4/MET and BOOTES-2/TELMA 0.6m automatic optical telescopes on Nov 25, 26, and 27. We did not detect any new optical source within localizationof the gamma ray source. The upper limits of magnitudes were calculated using six bright stars in the same frame and the APASS9 catalogue as reference. The upper limits of magnitudes (without being corrected for Galactic extinction) are given as follows. <p>

MJD-T0 (day) | UT(Start) | Upper Limits (mag) | Exposure Time | Filter | Telescope <p>

--------------------------------------------------------------------------------------------------------------<p>

0.86 | 2022-11-25T12:25:17.41 | 18.718 (0.04) | 11*30s | SDSS-i | BOOTES-4 <p>

0.87 | 2022-11-25T12:40:37.86 | 19.567 (0.07) | 8*30s | Clear | BOOTES-4 <p>

1.14 | 2022-11-25T19:04:23.56 | 18.756 (0.07) | 30*30s | SDSS-i | BOOTES-2 <p>

1.84 | 2022-11-26T11:52:03.53 | 19.347 (0.04) | 7*60s | SDSS-i | BOOTES-4 <p>

2.82 | 2022-11-27T11:29:08.99 | 19.80 (0.06) | 24*60s | SDSS-i | BOOTES-4 <p>

--------------------------------------------------------------------------------------------------------------<p>

 

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 BOOTE Network, BOOTES-4/MET, is located at the Lijiang Observatory of the Yunnan Observatories of China (Xiong et al. 2020). The BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain). <p>

 

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