When a massive star exhausts its nuclear fuel, it undergoes gravitational collapse, leading to a sudden and violent explosion known as a supernova.

Depending on the mass of the progenitor star, a supernova can leave behind a neutron star or a black hole. A supernova remnant is the expanding debris from the explosion.

Type II supernovae occur when massive stars (more than 8 solar masses) undergo core collapse and explode.

Type Ia supernovae are triggered by the thermonuclear runaway of carbon and oxygen in a white dwarf, leading to a rapid and explosive burning.

Type II supernovae are responsible for the production of heavy elements (elements heavier than iron) through nucleosynthesis during the explosion.

The average frequency of supernovae in our galaxy is estimated to be about once every 100 years.

The Crab Nebula is the most famous supernova remnant due to its association with the supernova observed by Chinese astronomers in 1054 AD and its unique properties, including a pulsar and a synchrotron nebula.

The Vela Supernova Remnant is the closest supernova remnant to Earth, located about 800 light-years away.

SN 1987A, a supernova in the Large Magellanic Cloud, provided strong evidence for the existence of neutrinos through the detection of a neutrino burst.

SN 1572, also known as Tycho's Supernova, was the first supernova to be observed with a telescope by Tycho Brahe in 1572.

Type Ia supernovae occur when a white dwarf accretes mass from a companion star, leading to a thermonuclear runaway and explosion.

SN 1006, also known as the 'Guest Star,' was a supernova that was visible in broad daylight in 1006 AD.

Type Ib and Type Ic supernovae occur when massive stars lose their outer layers through stellar winds, leaving behind a core that undergoes gravitational collapse and explosion.

SN 1994I, a Type Ia supernova, was used to measure the expansion rate of the universe and provided evidence for the accelerating expansion.

Type II supernovae occur when massive stars retain their outer layers and undergo gravitational collapse, leading to an explosion that ejects both the core and the outer layers.