Introduction to Supernovas and Neutron Stars

Supernova Classification

• Types of Supernovas:
  • Type I: Nothing remains after the explosion.
  • Type II: Remaining core, often leading to the formation of neutron stars.

Type II Supernova Process

• Core Collapse:

  • Happens when a massive star exhausts its nuclear fuel.
  • The iron core collapses under the influence of gravity, a process detailed in Chapter 12.

• Neutron Formation:

  • Gravity compresses the core until it collapses into neutrons.
  • At this stage, neutron degeneracy pressure halts the collapse, counteracting gravity.

• Shock Wave:

  • Following core rebound, a shock wave ejects surrounding material into space, resulting in a supernova explosion.

Characteristics of Neutron Stars

• Size:

  • Approximately 20 kilometers in diameter, comparable to a city like Brooklyn or Tampa.
  • Extremely dense; even a small amount has a mass greater than that of the Sun.

• Gravity:

  • Neutron stars possess intense gravitational fields; a human weighing 154 pounds would weigh approximately a billion pounds on its surface.

Properties of Neutron Stars

• Spin:

  • Neutron stars spin rapidly with rotation periods of just fractions of a second.

• Magnetic Field:

  • Possess a strong and tightly compressed magnetic field, enabling their detection from Earth.

Energy Generation in Massive Stars

• Massive stars produce energy through nuclear fusion until they reach a critical point, leading to rapid core collapse.
• The explosion is caused by the energy from the expanding shock wave detaching the outer stellar material.