Hanjie Tan (Institute of Astronomy, National Central University), Mi Zhang, Guoyou Sun, Jingyuan Zhao (Xingming Observatory), Quanzhi Ye , Xing Gao (Xingming Observatory), report ~3 mag outburst in a known variable star ( 16.97 r ) which is 20.02 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 Mar. 02.73083, 2021 UT using a unfiltered CCD ( 0.3-m f/3.6 reflector ). Images can be found at: http://xjltp.china-vo.org/xm56ht.html
XM56HT C2021 03 02.73083 07 50 14.72 +15 32 28.5 16.97 r N88
XM56HT C2021 03 02.74793 07 50 14.65 +15 32 28.9 17.35 r N88
*Known VS ASASSN-15tl
