[vsnet-grb-info 20099] GRB 171205A: GMG observations (2nd night)

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22195
SUBJECT: GRB 171205A: GMG observations (2nd night)
DATE:    17/12/07 07:00:13 GMT
FROM:    Jirong Mao at Yunnan Obs  <jirongmao_obs at ynao.ac.cn>

J. Mao, X. Ding and J.-M. Bai (YNAO) report:


We observed the field of GRB 171205A (D'Elia et al., GCN 22177) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG)
station of Yunnan Observatories, beginning from 22:04:14 UT, 6th, Dec., 2017, about 1.6 days after the trigger. We still clearly detected the optical counterpart. Some preliminary results were roughly estimated as B~20.7, V~20.0, and R~20.7 mag. The brightness might be underestimated due to poor seeing. Although the magnitudes we measured have large uncertainty, we compare our observation of the first night (Mao et al. GCN 22186), and it seems that the source has no significant fading evidence.