According to images obtained by the Hubble Space Telescope, 3 supernovae that were originally discovered several years ago have exploded in space, after they had been flung from their home galaxies millions or even billions of years prior.
A large majority of supernovae can be discovered inside galaxies surrounded by hundreds of billions of stars, one of which may just explode per century per galaxy.
What can these isolated stars tell us?
These isolated supernovae were discovered in between galaxies, and the rarity of these supernovae give us a key clue as to what lives in the expansive space in the middle of galaxies. These findings will also be able to assist astronomers in comprehending exactly how galaxy clusters first originally came together and how they evolved throughout the universe’s history.
The existence of the isolated pockets made study leader Melissa Graham think of the star Thrial – a fictional star which is located a million light years away from any other star, in the fictional novel Against a Dark Background penned by author Ian Banks.
Planets that are surrounding these intracluster stars saw their demise by the explosions. However, they would have left a night sky completely devoid of shining stars, Graham says. “We have provided the best evidence yet that intracluster stars truly do explode as Type Ia supernovae,” Graham said, going on to say that hostless supernovae can lead us to the population of other intracluster stars.
In addition, Graham and her colleagues stumbled upon a 4th exploding star, found by CFHT. This star apparently was inside of a red, round region that may be a galaxy small in size or a globular cluster. If it is indeed true that the supernova is part of the globular cluster, it would be the first time a supernova has exploded within the confines of these pocket-sized, compact clusters consisting of less than one million stars. All 4 supernovae were in galaxy clusters that were nearly a billion light years from Earth.
Other kinds of explosions
A Type II supernova explosion involves a star which has 9 times the solar mass, at the very least. When the star’s fuel is close to disappearing, the star will flare up and burst due to the core collapse. Types 1b and 1c involve the same type of star. A more lethal kind of explosion is the hypernova, which has an energy 50 times more powerful than other supernovas, and can result in a black hole.