Scientists have discovered the most distant star observed to date, a blue supergiant. The far-distant star, observed with the Hubble Space Telescope, is at 9 billion light-years away from Earth.
This distance means that the star started to exist about 4,800 million light years after the Big Bang when the Universe was only one-third of its current age. Named ‘Icarus’, this distant star is located in a galaxy far away, behind the cluster of galaxies’ MACS J1149-2223.
The discovery of this star, which was formally called MACS J1149 Lensed Star 1 (LS1), initiates a new technique for astronomers to study individual stars in galaxies formed during the first stages of the Universe.
These observations can provide an exceptional look at how stars evolve, especially about the brightest ones
In April 2016, scientists made observations with the Hubble Space Telescope and detected the appearance of the supernova explosion SN Refsdal, named after the late Norwegian astrophysicist Sjur Refsdal.
On the other hand, a supernova has been discovered in 2014, also with the help of the Hubble. But an unexpected source of light was detected in the same galaxy where the supernova was found.
Suspecting that Icarus could be more magnified than ‘SN Refsdal’, the scientists analyzed the colors of the light that came from it and discovered that it was a very rare star – a blue supergiant. Even more, Icarus is the most distant star ever discovered.
This type B star is much larger, more massive, hotter, and possibly hundreds of thousands of times intrinsically brighter than the Sun.
The star was observed thanks to the gravitational lens effect
This star has been detected thanks to the so-called gravitational lens effect, a phenomenon that is produced by a cluster of galaxies, with a mass 1,000 times the mass of the Sun, which amplifies the light that occurs in objects that are far away and aligned just behind of the cluster, generating an effect similar to what a lens would do.
This allows making visible all the dark and distant objects. Typically, this phenomenon amplifies galaxies up to 50 times, but in this case, the star was amplified more than 2,000 times.
In conclusion, scientists, using the Hubble Space Telescope, have discovered the most distant star to date, called Icarus. Plus, Icarus has been proved to be a very rare star, too, a blue supergiant.