The Crab Pulsar is the neutron star left by the supernova SN 1054, a city-sized core spinning many times a second at the heart of the Crab Nebula.
At a glance
| type | neutron star (pulsar) |
|---|---|
| distance from the Sun | 6,520 light-years (2 kpc) |
| its light left it | 6,520 years ago |
| luminosity | 3.5 × the Sun |
| radius | 0.0000144 × the Sun (10 km) |
| surface temperature | 20,000 K |
Read off the piece’s own catalogue, the same values it draws with.
About Crab Pulsar
When a massive star exploded, its core collapsed into a neutron star: a ball of matter denser than an atomic nucleus, more massive than the Sun yet only the size of a city. The explosion, SN 1054, was recorded by Chinese astronomers in the Middle Ages as a new star visible in daylight; its debris is the Crab Nebula, M1, in Taurus.
The neutron star spins rapidly and its magnetic field sweeps beams of radiation across the sky, so we see it pulse, in radio, visible light, X-rays and gamma rays. It is one of the few pulsars whose flashes have been seen in visible light.
Its spin is slowing, and the energy it loses powers the nebula, making electrons spiral in magnetic fields and shine with the bluish glow seen at the centre of the Crab.
What you see in the piece
Fly to the Crab Nebula and the pulsar is an almost invisible point at its centre; it is tiny, and most of its energy goes into the nebula, not its own light.
Questions
How big is the Crab Pulsar?
Only about 0.0000144 × the Sun (10 km) in radius, about the size of a city, though more massive than the Sun.
How far away is the Crab Pulsar?
It is 6,520 light-years (2 kpc) from the Sun, so the light of the supernova that made it had travelled that long before it reached Earth.