Uber Bright Supernova is a stellar mystery

Uber Bright Supernova is a stellar mystery

A network of small ground-based telescopes-hunters of the latest generation of night vision recently managed to detect another supernova — a unique cosmic explosion that emits 50 times more light at the time of its maximum than all the Milky Way stars combined.

The flash, now referred to as ASASSN-15lh, is the supernova. It was first seen on June 14, 2015. A week before, the young scientist Subo Dong from Peking University of Astronomy and Astrophysics, watching the cosmos, noticed sudden light interruptions in it and immediately suspected that something more than strange was happening.

“The measurements were so sharp and fast that the automated software didn’t even recognize a supernova at first,” Dong Discovery News wrote in an e-mail.

“We have been discussing the phenomenon with colleagues for a long time and could not decide on its origin. We looked through all the options, but none came up,” said Don.

Working with colleagues in observatories around the world stumbled upon Dong to the idea that the object probably belongs to a rare class of so-called supernovae. Suspicions were confirmed after research conducted in South Africa with the help of a 10-meter latest telescope.

“Looking at the spectrum of the lens, we immediately realized that we had found something big,” said Don.

ASASSN-15lh is about 3, 8 billion light years from Earth, but it shines brightly. If it were located somewhat closer to us, like Sirius, it could fulfill the role of the Sun or replace it altogether. Its light is 200 times more powerful than the average supernova, and more than two times brighter than the last discovered supernova.

Scientists are not able to name the cause of the explosion. One theory says that a dense, rapidly rotating neutron star, known as “magnetar”, feeds the supernova. The rotation speed reaches at least 1000 times per second. This is a clear challenge to all the laws of physics. In addition, it can be said with confidence: when the magnetar is rotated, energy is converted into light.

Another option: the supernova ASASSN-15lh is powered by some nuclear reactions associated with a supermassive black hole in the center of its galaxy. But at the moment, scientists do not know anything about such a phenomenon, just as they do not know about the exact location of the very black hole. More information is expected this year from the Hubble Space Telescope.

“Hubble must answer precisely: whether this event occurred right in the galactic core or it is offset from the center. If the phenomenon occurred outside the center, this eliminates the connection of this event with the central supermassive black hole near the host galaxy,” astronomer wrote in an e-mail to Discovery News Todd Thompson from Ohio.

“What can a supermassive black hole activity lead to? We don’t know, since we never saw something like that. Our colleagues called the flash a“ tidal breaking wave of light ”- a very bright explosion that occurs when a large old or young star explodes. it explodes, a new black hole appears in its place. The problem is that no one had previously observed a similar phenomenon, which would have been similar to an ASASSN-15lh outbreak. In particular, most of the stars consist mainly of hydrogen and helium, and the ASASSN spectra -15lh not show n There are no signs of these substances, "Thompson said. The supernova galaxy itself is another smaller mystery. Most supernovae are located in small dwarf galaxies, where active stellar formation occurs. ASASSN-15lh, unlike its relatives, has a huge galaxy, about three times the entire mass of the Milky Way.

Scientists have eliminated the possibility that a brighter outbreak of a supernova will occur, which will subsequently affect other galaxies and such a phenomenon as a gravitational lens.

“The good news is that bright ASASSN-15lh can be relatively easy to observe and receive high-quality observations and photographs from it. Many groups of astronomers, using some of the most advanced ground-based and space-based telescopes to study ASASSN-15lh, are certain: in the near future we will be able to study this phenomenon many times better and in more detail. Perhaps something new about our Universe will be revealed to us. "

These studies are the focus of talk this week.

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