Once they reach the end of their lives, massive stars (about eight times more massive than our Sun) explode in supernovae. The explosions leave behind a black hole or neutron star and are so energetic that they can outshine their host galaxies for a long time. However, astronomers seem to have spotted a massive star that skipped the explosion stage and turned straight into a black hole.
Stars are a balancing act between the external force of fusion and the internal force of gravity. When they reach the last stage of their evolution, massive stars begin to run out of hydrogen and fusion slows down.
The external force can no longer counteract the strong gravity of the star, and so it collapses. The result is a supernova explosion, a catastrophic event that destroys the star and leaves behind a black hole or neutron star.
The disappearance of a massive star in the Andromeda galaxy
However, it appears that sometimes stars stop exploding into supernovae and instead become black holes directly, they report Phys.org.
New research shows how a super-giant star in the Andromeda galaxy (M31) stopped detonating in a supernova. The study, published in the preprints server arXiv with the title „The disappearance of a massive star marking the birth of a black hole in M31” (The disappearance of a massive star marks the birth of a black hole in M31), was coordinated by Kishalay De, a researcher at the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology (MIT).
Such a supernova occurs once every 100 years or so
These types of supernovae are known to astronomers as Type 2 supernovae, being relatively rare. In the Milky Way galaxy, such a supernova occurs about once every 100 years. Scientists are interested in learning more about Type 2 supernovae because they produce many of the heavy elements, and their shock waves can trigger star formation. These supernovae also generate cosmic rays that reach Earth.
However, the new study shows that we may not understand them as well as we thought.
“The dramatic and sustained diminution of (the star) M31-2014-DS1 is exceptional”
The star in the present case is named M31-2014-DS1. For 1,000 days, its brightness was constant. Then, for another 1,000 days between 2016 and 2019, the light dimmed considerably. The star is variable, but that doesn’t explain the brightness fluctuations. In 2023, the star was no longer detected in the researchers’ observations.
“The dramatic and sustained diminution of (the star) M31-2014-DS1 is exceptional in the landscape of variability in evolved massive stars. The sudden decline in luminosity indicates the cessation of nuclear combustion along with an aftershock,” the study authors wrote.
Ancient astronomers documented many such cosmic events
“With no evidence for a light burst at such close proximity, the observations of M31-2014-DS1 indicate the signatures of a failed supernova,” the researchers explained.
However, M31-2014-DS1 is not the only failed supernova, or failed supernova candidate, that astronomers have discovered. These are hard to find because you have to look for something not it happened On the other hand, a supernova is hard to ignore because it is so bright and appears suddenly in the sky. Ancient astronomers documented several such cosmic events.
In 2009, astronomers discovered the only confirmed failed supernova ever, a red giant in Galaxy 6946, or the Fireworks Galaxy. After suddenly disappearing, the star left behind only a reddish glow.
We also recommend that you read:
A team of astronomers would have solved the mystery of the age of the Milky Way! How old is our galaxy?
The Webb Telescope has discovered something unprecedented in a bizarre galaxy
Astronomers used the Webb Telescope to observe a galaxy that grew ‘upside down’
The most distant disk galaxy ever observed is an oddity of the Universe
Source: www.descopera.ro
