(ORDO NEWS) — The gravitational lens made it possible to see a supernova that erupted in the young Universe, more than 11 billion years ago. It appeared as a result of the explosion of a red supergiant hundreds of times larger than the Sun.
Gravity distorts the flight paths of photons, due to which sufficiently massive space objects can play the role of natural lenses , distorting and enlarging the image of the bodies behind them.
The authors used gravitational lensing of the large galaxy cluster Abell 370 to view an ancient supernova behind it and estimate its size.
The Abell 370 cluster contains hundreds of galaxies and is almost five billion light-years away. However, the supernova, for which it acted as a gravitational lens, is located much further, at 11.5 billion light years.
It broke out even when the universe was about two billion years old. At the same time, this process is captured on the new images three times at once, at different moments of its development.
Due to the fact that the radiation could travel through the gravitational lens in different ways, the distance it traveled turned out to be slightly different.
Therefore, the lenses of the telescopes (the authors of the work used the space Hubble, as well as the ground-based Large Binocular Telescope of the American Mount Graham Observatory) received photons emitted at slightly different stages of the supernova explosion, separated by several days.
They show both the very first steps with bright radiation in the blue part of the spectrum, and the next moments when the light turns into red, less energetic light.
“It’s rare to see a supernova at this early stage because it doesn’t last long,” said Wenlei Chen of the University of Minnesota, one of the authors of the paper.
“Everything lasts for hours or days, which are easy to miss. But in the same exposure, we got a sequence of three images at once, different “faces” of the supernova.”
Based on the brightness, rate of extinction and other parameters of a distant supernova, scientists were able to estimate the size of a star that exploded billions of years ago.
It became the most distant supernova for which it was possible to carry out such calculations. Judging by the results, the radius of the star exceeded 530 solar radii.
She belonged to the class of red supergiants , similar to the current Betelgeuse, which is also expected to soon become a supernova.
Contact us: [email protected]