Hanjie Tan (Institute of Astronomy, National Central University), Mi Zhang, Guoyou Sun, Jingyuan Zhao (Xingming Observatory), Quanzhi Ye , Xing Gao (Xingming Observatory), report ~0.8 mag outburst in a variable star candidate (G=17.11+-0.06). The source appears to correspond to object Gaia DR2 919044493638410624 (G=17.89) in the Gaia DR2. Discovery was made on several 120-s survey images (limiting mag about 18.0) taken by Xing Gao at Xingming Observatory #3 (N88) around Sep. 04.88, 2021 UT using a unfiltered CCD (0.3-m f/3.6 reflector). Images can be found at: http://xjltp.china-vo.org/xm70ht.html
XM70HT C2021 09 04.88029 07 50 00.94 +36 55 12.6 17.11 G N88
XM70HT C2021 09 04.89736 07 50 00.92 +36 55 14.5 17.74 G N88
