1. Middleweight Stars
4-12 solar masses

2. Carbon nuclei attempt fusion
Electrons and protons fuse to become neutrons.
Outer layers are ejected due to backward pressures.

3. Two results: Rapidly rotating neutron star- large magnetic field.
A)If no companion, star may collapse on itself catastrophically.
Type II Supernova
(1054A.D. Crab Nebula was first seen. )

5. B) If neutron star has companion, charge particles collide on NS due to B-field.
The released energy radiates away from the star.
The rapid rotation periodically “pulses”
Pulsars (When the energy radiates in the X-Ray region, they call it an X-ray pulsar.

6. Pulsars can exist in other electromagnetic regions.
Radio, x-ray (hercules X-1)

7. Greater than 12 solar masses
Heavyweight Stars
Greater than 12 solar masses

8. Star allows fusion beyond carbon.
Iron nuclei form in the core.
Core collapses due to intense gravity.
Backward radiation blows lighter elements
Nucleosynthesis- formation of heavier elements from lighter due to the shockwave of the explosion.

9. The core’s gravity becomes very intense.
When gravitational field becomes so intense, light cannot escape.
Blackhole is formed.

10. Stellar remnants Planetary nebula White Dwarf
Black dwarf or Type I supernova
Neutron star
Type II supernova
Black hole