Messier 106 (also known as NGC 4258) is a spiral galaxy in the constellation Canes Venatici. It was discovered by Pierre Méchain in 1781. M106 is at a distance of about 22 to 25 million light-years away from Earth. It is also a Seyfert II galaxy. Due to x-rays and unusual emission lines detected, it is suspected that part of the galaxy is falling into a supermassive black hole in the center NGC 4217 is a possible companion galaxy of Messier 106. A Type II supernova was observed in this galaxy in May 2014.