Using the Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) onboard the NASA/ESA/CSA James Webb Space Telescope, astronomers are searching for answers about the origins of the Crab Nebula, the remnant of a Type II supernova that was first observed by Chinese astronomers on July 4, 1054 CE, as a ‘guest star.’
This composite image, taken by Webb’s NIRCam and MIRI instruments, shows the famous Crab Nebula. Image credit: NASA / ESA / CSA / Webb / STScI / Tea Temim, Princeton University.
The Crab Nebula is the result of a bright supernova explosion seen by Chinese, Japanese, Arabic, and Native American stargazers in 1054 CE.
Bright enough to be visible in amateur telescopes, this object lies 6,500 light-years away in the constellation of Taurus.
Also known as Messier 1, NGC 1952 or Taurus A, it was first identified in 1731 by the English astronomer, doctor and electrical researcher John Bevis.
In 1758, while searching for a comet, the French astronomer Charles Messier rediscovered the hazy nebula. He later added the object to his celestial catalog as Messier 1, marking it as a ‘fake comet.’
The nebula derived its name from its appearance in a drawing made by Irish astronomer Lord Rosse in 1844.
“Webb’s sensitivity and spatial resolution allow us to accurately determine the composition of the ejected material, particularly the content of iron and nickel, which may reveal what type of explosion produced the Crab Nebula,” said Princeton University astronomer Tea Temim.
At first glance, the general shape of the Crab Nebula is similar to the optical Hubble image released in 2005.
“In Webb’s infrared observation, the crisp, cage-like structure of fluffy gaseous filaments are shown in red-orange,” the astronomers said.
“However, in the central regions, emission from dust grains (yellow-white and green) is mapped out by Webb for the first time.”
“Additional aspects of the inner workings of the Crab Nebula become more prominent and are seen in greater detail in the infrared light captured by Webb.”
“In particular, Webb highlights what is known as synchrotron radiation: emission produced from charged particles, like electrons, moving around magnetic field lines at relativistic speeds.”
“The radiation appears here as milky smoke-like material throughout the majority of the Crab Nebula’s interior.”
“This feature is a product of the nebula’s pulsar, a rapidly rotating neutron star.”
“The pulsar’s strong magnetic field accelerates particles to extremely high speeds and causes them to emit radiation as they wind around magnetic field lines.”
Though emitted across the electromagnetic spectrum, the synchrotron radiation is seen in unprecedented detail with Webb’s NIRCam instrument.
“To locate the Crab Nebula’s pulsar heart, trace the wisps that follow a circular ripple-like pattern in the middle to the bright white dot in the center,” the researchers said.
“Farther out from the core, follow the thin white ribbons of the radiation.”
“The curvy wisps are closely grouped together, outlining the structure of the pulsar’s magnetic field, which sculpts and shapes the nebula.”
“At center left and right, the white material curves sharply inward from the filamentary dust cage’s edges and goes toward the neutron star’s location, as if the waist of the nebula is pinched.”
“This abrupt slimming may be caused by the confinement of the supernova wind’s expansion by a belt of dense gas.”
“The wind produced by the pulsar heart continues to push the shell of gas and dust outward at a rapid pace.”
“Among the remnant’s interior, yellow-white and green mottled filaments form large-scale loop-like structures, which represent areas where dust grains reside.”