Hanjie Tan, Guoyou Sun, Mi Zhang, Xing Gao (Xingming Observatory), report ~2.9 mag outburst in a known variable star ( 17.55 r ) which is 20.45 rmag in Pan-STARRS DR1 catalogue. The transient was discovered on several 120-s survey images ( limiting mag about 18.0 ) taken by Xing Gao at Xingming Observatory #3 ( N88 ) around Jan. 04.75723, 2021 UT using a unfiltered CCD ( 0.3-m f/3.6 reflector ). Images can be found at: http://xjltp.china-vo.org/xm31ht.html
XM31HT C2021 01 04.75723 08 20 19.37 +47 47 31.0 17.55 r N88
XM31HT C2021 01 04.77444 08 20 19.36 +47 47 31.0 17.74 r N88
*Known VS CSS 091213:082019+474732
