Hanjie Tan (Institute of Astronomy, National Central University), Mi Zhang, Guoyou Sun, Jingyuan Zhao (Xingming Observatory), Quanzhi Ye (Department of Astronomy, University of Maryland), Xing Gao (Xingming Observatory), report the outburst in a supernova candidate (17.96 r). 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 Apr. 20.82238, 2021 UT using a unfiltered CCD (0.3-m f/3.6 reflector). Images can be found at: http://xjltp.china-vo.org/xm68ht.html
XM68HT C2021 04 20.82238 17 04 36.15 +30 52 31.9 17.96 r N88
