My own current neighborhood fits this definition of a suburb that lacks the negative aspects of postwar sprawl. A 20-minute train ride from the center of Philadelphia, it boasts a retail and small office district within a short walk of most homes.
Crab supernova remnant: A supernova is an explosion of a massive supergiant star. It may shine with the brightness of 10 billion suns! The total energy output may be 10 44 joules, as much as the total output of the sun during its 10 billion year lifetime. The likely scenario is that fusion proceeds to build up a core of iron.
Above 8 solar masses, they explode as supernovae. Between 8 and 15 solar masses the remnant of the explosion ends up as a neutron star; above about 15 solar mass, the remnant collapses catastrophically to become a black hole To clarify the Type 1a vs Type 2 supernovae-massive stars end up as type 2 supernovae.eport Abuse. A small star will go nova, leaving behind a small dwarf star, usually a white dwarf. A very large star will go supernova, and could possibly leave behind a neutron star or a black hole.