IAUC No. 6524 reports the discovery of by M. Aoki (Toyama, Japan) of a supernova in NGC 3510.
11h 03m 41s.98 (J2000.0) +28o 54' 13".7 mag 16.5 on Dec. 15.707 type II 20".9 west and 65".7 north of the galaxy center
The supernova seems to have brightened further as the CCD observation at Ouda Station suggests:
VSNET chart: