The Hubble Telescope has captured another stunning image of outer space with its photograph of the heart of the Crab Nebula, a pulsing neutron star surrounded by swirling clouds of rainbow-colored gas.
The Crab Nebula was created by a supernova, or the explosion of a massive star, the remnants of which remain at the center of the nebula in the form of a neutron star: a fast-spinning, compressed ball of subatomic particles called neutrons.
“The neutron star is a showcase for extreme physical processes and unimaginable cosmic violence,” wrote NASA in a statement. “Bright wisps are moving outward from the neutron star at half the speed of light to form an expanding ring. It is thought that these wisps originate from a shock wave that turns the high-speed wind from the neutron star into extremely energetic particles.”
Located in the constellation Taurus, the Crab Nebula was formed during one of the first supernovae to be recorded in human history. Asian astronomers noticed a new massively bright star in the night sky in 1054.
The records that these astronomers left behind indicate that this star was the brightest object in the sky (excluding the Moon) for a brief time, until it began to fade, and eventually disappeared from view.
The massive explosion – the death throes of the dying star – left behind an enormous cloud of expanding gas, known as a supernova remnant.
That cloud of gas, now known as the Crab Nebula, is strikingly beautiful and often photographed, although most photographs capture the outer parts of the nebula, with their colorful filaments of ionized gas.
Hubble's latest triumph, a composite of three separate photographs stitched together into a cohesive image, reveals what Hubble scientists called "the beating heart" of the nebula: the pulsing neutron star that remains from the supernova.
The Crab Nebula’s neutron star is a "pulsar," a star that channels gas and dust to the star’s poles and sends the material out into space in a rotating beam of electromagnetic radiation that scientists compare to a lighthouse beam.
The spinning heart that powers this rotates around 30 times per second. Like all neutron stars, it is unbelievably dense, containing about the same amount of mass as our Sun, condensed into a spinning ball of neutrons about 10 miles across.
Just how dense is that? As Cornell astronomers explain, "A teaspoon of neutron star material would weigh about 10 million tons."
Nebulae are colorful phenomena all around. The blue glow of the gas closest to the neutron star is radiation given off by electrons in the star’s magnetic field. The surrounding gases are also colorful, appearing to swirl with rainbow colored filaments as the gas moves.
“The rapid motion of the material nearest to the central star is revealed by the subtle rainbow of colors," wrote the European Space Agency, caused by "the movement of material over the time between one image and another."