GCN Circular 18493
J. Zhang, J. Mao and J. Bai (YNAO) report: We observed the field of GRB 151027A (Maselli et al., GCN 18478) with the 2.4-meter optical telescope at Gao-Mei-Gu of Yunnan Observatories. Observations began at 11:34:08 UT, Oct 27, 2015, about 7.5 hr after the trigger. We obtained a low S/N spectrum. The feature of absorption line identified as MgII by Perley et al. (GCN 18487) is clearly shown, and redshift is 0.81. However, we noticed that some possible absorption lines might be identified as OVI and NaID, indicating a redshift of 0.33. We cannot have confirmation due to the low S/N of the spectrum. We also performed multi-band photometry and we obtained R~16.9 mag. Further analysis is ongoing.