Q: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
This object once crashed into the Maffei I group, ejecting the latter from its group. Companions to this object include the Pegasus and Cassiopeia dwarves. The bright globular cluster G1, also known as Mayall II, is in this object. In 1991, this object was discovered to have a double nucleus. This object's apparent neighbor, the Triangulum galaxy, may be gravitationally bound to it. Edwin Hubble discovered the first Cepheid variable in this galaxy, proving that it was not a star cluster in the Milky Way. Named for and contained in a constellation including Sirrah, for 10 points, name this large member of the Local Group, the nearest spiral galaxy to the Milky Way.
A:
Science