Hanjie Tan, Guoyou Sun, Mi Zhang, Jingyuan Zhao, Jiangao Ruan, Xing Gao (Xingming Observatory), report ~2 mag outburst in a known variable star ( 18.55 r ) which is 20.64 rmag in Pan-STARRS DR1 catalogue. The transient was discovered on several 120-s survey images ( limiting mag about 19.0 ) taken by Xing Gao at Xingming Observatory #3 ( N88 ) around Feb. 15.65799, 2021 UT using a unfiltered CCD ( 0.3-m f/3.6 reflector ). Images can be found at: http://xjltp.china-vo.org/xm53ht.html
XM53HT C2021 02 15.65799 06 43 13.84 +18 59 51.6 18.55 r N88
XM53HT C2021 02 15.65799 06 43 13.81 +18 59 51.6 18.27 r N88
*Known VS BMAM-V733