
Return	TYPE II Supernovae Normal stellar evolution runs from Main Sequence stars (core hydrogen burning) ===> Red Giant phase ===> helium core burning ===> Asymptotic Giant Branch ===> higher nuclear burning stages. The normal nuclear lifetime of a star ends after its core has been converted to iron. At this point, the core has mass M_core ~ 1.2-2 M_o and radius R_core ~ 1,000 km. The core next collapses; the collapse is driven by photodissociation and/or electron captures which drives the pressure in the core down causing the run-away gravitational collapse of the core. For a nonrotating star, collapse continues until nuclear density is reached where the EOS stiffens. The collapse to nuclear density is very quick. It takes less than ~ 1 s. An accretion shock then forms as the outer core settles onto the inner core. The shock subsequently moves outward through the accreting material and the surrounding stellar mantle. Under the right conditions, the shock ejects the outer layers of the star leading to a Type II Supernova outburst.

TYPE II Supernovae

Normal stellar evolution runs from Main Sequence stars (core hydrogen burning) ===> Red Giant phase ===> helium core burning ===> Asymptotic Giant Branch ===> higher nuclear burning stages. The normal nuclear lifetime of a star ends after its core has been converted to iron. At this point, the core has mass M_core ~ 1.2-2 M_o and radius R_core ~ 1,000 km.

The core next collapses; the collapse is driven by photodissociation and/or electron captures which drives the pressure in the core down causing the run-away gravitational collapse of the core.
For a nonrotating star, collapse continues until nuclear density is reached where the EOS stiffens. The collapse to nuclear density is very quick. It takes less than ~ 1 s. An accretion shock then forms as the outer core settles onto the inner core. The shock subsequently moves outward through the accreting material and the surrounding stellar mantle. Under the right conditions, the shock ejects the outer layers of the star leading to a Type II Supernova outburst.