August 23, 2024
Billions of years of cosmic evolution — the birth and death of stars, the slow coalescence of planets, the patient unfolding of life — all...
Supernova Remnant CTA 1
Birthday · August 23, 2024
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APOD published August 23, 2024. Credit: Thomas Lelu. A publication-date match, not a photo taken on your date. Independent of NASA.
There is a quiet pulsar at the heart of CTA 1. The supernova remnant was discovered as a source of emission at radio wavelengths by astronomers in 1960 and since identified as the result of the death explosion of a massive star. But no radio pulses were detected from the expected pulsar, the rotating neutron star remnant of the massive star's collapsed core. Seen about 10,000 years after the initial supernova explosion, the interstellar debris cloud is faint at optical wavelengths. CTA 1's visible wavelength emission from still expanding shock fronts is revealed in this deep telescopic image, a frame that spans about 2 degrees across a starfield in the northern constellation of Cepheus. While no pulsar has since been found at radio wavelengths, in 2008 the Fermi Gamma-ray Space Telescope detected pulsed emission from CTA 1, identifying the supernova remnant's rotating neutron star. The source has been recognized as the first in a growing class of pulsars that are quiet at radio wavelengths but pulse in high-energy gamma-rays.
Image credit: Thomas Lelu