A Cosmic Lighthouse 6,500 Light Years Away
Aftermath
The Crab Nebula provides scientists with a natural laboratory for studying:
Stellar death and supernova mechanics
High-energy astrophysics
Magnetic field interactions in space
It was first observed on Earth in 1054 AD, recorded by Chinese astronomers and others. Said explosion marked the catastrophic end of a massive star's life, ejecting its outer layers into space while collapsing its core.
Distance and Scale
Located approx 6,500 light-years away in the constellation Taurus, the Crab Nebula spans about 11 light-years across. It continues to expand at a rate of 1,500 kilometres per second, and the glowing filaments seen in the image are made of ionised gases—mainly hydrogen, helium, carbon, oxygen, nitrogen, and sulfur.
The Neutron Star (Pulsar) at Its Core
At the heart of the nebula lies the Crab Pulsar, a neutron star formed from the collapsed core of the progenitor star. A neutron star is incredibly dense—about 1.4 times the mass of the Sun, but only 20 kilometres in diameter. A teaspoon of its material would weigh over a billion tons on Earth.
This neutron star is also a pulsar, meaning it emits beams of electromagnetic radiation from its magnetic poles. As it rotates around 30 times per second, these beams sweep across space. When aligned with Earth, the beam appears to pulse—hence the name "pulsar."
A Cosmic Lighthouse
The pulsar emits radiation across the electromagnetic spectrum, including radio waves, visible light, X-rays, and gamma rays. It functions like a cosmic lighthouse, with each pulse marking a rotation. These emissions energise the surrounding nebula, causing the vivid glow captured in multi-wavelength observations, such as the one in the image.
Recommended Resources
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HiRISE (High Resolution Imaging Science Experiment | Mars Reconnaissance Orbiter)