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.

Whiskers form on the face of these structures due to the polymerization cause by thousand-gauss magnetic fields, and binary x-ray sources occur when these objects compress accreted material from their companions. Their size can be abruptly changed by starquakes, and their cores contain particles made up of only strange quarks, called hyperons. Their outer layers are about a half mile of iron; in between is a superfluid. Their mass must be below the indeterminate Oppenheimer-Volkoff limit, but above the Chandrasekhar limit, and they include soft gamma repeaters, magnetars, and pulsars. For 10 points, name these twelve-mile-wide, very dense stars, composed mostly of chargeless baryons.
Science