Divided into two broad classes by how they form, they are caused by either the transfer of matter from a main sequence star to its binary white dwarf companion, or the formation of an [i] iron core.
Divided into two broad classes by how they form, they are caused by either the transfer of matter from a main sequence star to its binary white dwarf companion, or the formation of an [i] iron core. The most famous one occurred in 1054—one of seven recorded before the 17th century—and its remnants are visible today as the Crab Nebula. With an absolute magnitude around negative 15—for 10 points—name these  violently exploding stars.
Divided into two broad classes by how they form, they are caused by either the transfer of matter from a main sequence star to its binary white dwarf companion, or the formation of an [i] iron core.
supernova(s) or supernovae [do not  prompt on “nova”]