- Remnant of cores of massive stars, left over after the core collapses in the supernova explosion
- 1.5x more massive than the Sun, only 10 km in radius
- 1 cm³ = 1 billion tons
- How to Detect Them
- Pulsars: spinning neutron stars that emit radio waves
- X-Ray Binaries: in a binary star system, accretes matter from the other star
Pulsars: In 1967, Jocelyn Bell discovered that a radio source emitted regular “pulses” of radio waves every 1,337 seconds, like clockwork. A pulsar is a rotating neutron star (e.g. Crab Pulsar). Its strong magnetic field generates radio emission. Since a beam of radio waves “sweeps” past us as the star rotates, the neutron star appears to change in luminosity.
X- Ray Binaries: In a binary star system, a neutron star can accrete mass spilling off of a companion star. There may also be black holes in x-ray binaries (e.g. GS2000+25)