Taurus Hill Observatory research team photographed NGC 3172 24./25.2.2010. At that time the team didn’t notice any supernovae in the galaxy. Tom Boles phographed same galaxy 4.3.2010 and he saw a faint supernova (about 17 mag.) fairly long distance from the center of the galaxy. THO reasearch team photographed the supernova 6.3.2010 and it was very visible in photographed pictures. After this it turned out that the supernova was also visible in pictures taken 24./25.2.2010. It was only 18.5 magnitudes and therefore the discovery wasn’t made by the THO research team. So the pictures taken 24./25.2.2010 were marked as prediscovery.