These phenomena often occur when a lack of electron degeneracy pressure causes core collapse to a neutron star.
The remnants of these phenomena may undergo the Sedov-Taylor phase before experiencing the snowplow phase. Wolf-Rayet stars are the progenitors to one type of these phenomena, and the presence of hydrogen absorption lines in their spectra leads to their Type II designation. The Type Ia ("one-A") of these phenomena is created after the mass of a white dwarf in a binary system exceeds the Chandrasekhar limit. The Crab Nebula is a remnant of one of these phenomena that occurred in 1054. These phenomena often occur when a lack of electron degeneracy pressure causes core collapse to a neutron star. For 10 points, name these luminous stellar explosions.
The remnants of these phenomena may undergo the Sedov-Taylor phase before experiencing the snowplow phase.
supernovas [or supernovae; or SNe]