Given the task definition and input, reply with output. 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.

It exists because of electron degeneracy pressure; as electrons are compressed closer together, more exist per unit volume and must take on higher energy levels as mandated by the Pauli-exclusion principle. A relativistic state equation can be used to calculate it as the radius of a white dwarf decreases with an increase in its mass. Developed shortly before its namesakes theory on black holes, for ten points, name this value of about 1.4 solar masses, the maximum mass of a star which can be supported against gravitational collapse.

Science