Elusive new type of supernova, long sought by scientists, actually exists
By Charles Q. Choi about 15 hours ago
The existence of electron-capture supernovas may explain the Crab Nebula
(Image credit: NASA/STSCI/J. Depasquale; Las Cumbres Observatory)
Astronomers may have finally discovered convincing evidence of an elusive kind of supernova, one that could explain a bright explosion that lit up the night sky on Earth nearly 1,000 years ago and birthed the beautiful Crab Nebula, a new study finds.
Supernovas are giant explosions that can occur when stars die. These outbursts can briefly outshine all of the other suns in these stars' galaxies, making them visible from halfway across the universe.
For decades, scientists have known of two main supernova types. Large stars more than 10 times the mass of the sun collapse in their centers when their cores burn all their fuel, causing the outer layers to explode and leaving behind a neutron star or black hole. In contrast, stars less than eight times the sun's mass burn out over time to leave a dense core of ash known as a white dwarf, and these remnants can pull fuel onto themselves off companion stars until they detonate in a thermonuclear explosion.
A different kind of supernova
An artist's impression of a super-asymptotic giant branch star (left) and its core (right) made up of oxygen (O), neon (Ne), and magnesium (Mg). These stars, around 8-10 solar masses, can explode in so-called electron-capture supernovas. (Image credit: S. Wilkinson; Las Cumbres Observatory)
Stars between eight and 10 solar masses should theoretically explode in a different way. Their gigantic internal pressures would force electrons to fuse with atomic nuclei. These electrons normally repel each other, so their removal leads to a drop in pressure inside the star. The star's core then collapses, setting off an explosion of the surrounding layers and leaving behind a neutron star slightly more massive than the sun.
More:
https://www.space.com/new-supernova-type-discovery?utm_source=Selligent&utm_medium=email&utm_campaign=SDC_Newsletter&utm_content=SDC_Newsletter+&utm_term=3403514&m_i=gOxgBvXShqGHUgVAPfckBIxOKJnyhAsgKZBDLWyFP6a_6tCGQw10HwR6FgsVk2wHNlDewSEQkJzK3hWYFBD%2BCyQ7eE12cnKKNjoAwLhgga&lrh=d43f3ce40e3ceae0368b3520fbc367f28c0c5e819c08493f82fed375e81c28a1
