Hanjie Tan, Guoyou Sun, Mi Zhang, Xing Gao (Xingming Observatory), report ~4.3 mag outburst in a known variable star ( 15.18 r ) which is 19.49 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 Dec. 28.52120 UT using a unfiltered CCD ( 0.3-m f/3.6 reflector ). Images can be found at: http://xjltp.china-vo.org/xm24ht.html
XM24HT C2020 12 28.52120 19 30 11.56 +46 59 28.3 15.18 r N88
*Known VS MGAB-V252
