NASA’s Hubble Space Telescope has just laid its… lens on a giant blue star nicknamed Icarus, that’s halfway across the universe. Astronomers say it’s the most distant star that has been observed so far and it was all possible through a phenomenon called “gravitational lensing”.
According to NASA’s discovery, they said that Icarus “is so far away that its light has taken 9 billion years to reach Earth. It appears to us as it did when the universe was about 30 percent of its current age”.
Hotter, Bigger, Brighter than the Sun
Dr. Patrick Kelly (University of Minnesota, Twin Cities) who’s behind the discovery, said that it “is the first time we’re seeing a magnified, individual star”. Although it’s possible to see individual galaxies, there’s something unique about Icarus, continues Dr. Patrick Kelly:
“You can see individual galaxies out there, but this star is at least 100 times farther away than the next individual star we can study, except for supernova explosions.”
Two years ago, Kelly and his team used Hubble to check a supernova. That’s when they saw a point of light close to the magnified supernova. After analyzing its colors of the light that came from that object, they realized they were looking at a blue supergiant star.
This huge star was hundreds of times brighter, larger and hotter than the sun. Also, Icarus was not a supernova, because, he said that “the source isn’t getting hotter; it’s not exploding. The light is just being magnified. And that’s what you expect from gravitational lensing.”
Comparing Distant Stars to Stars in the Milky Way
Dr. Louise Howes (Lund University, Sweden) also stated that the discovery is remarkable, but Icarus is a young star that, looking how it brightly burns, will die young.
Nonetheless, Howes said that such a discovery “is a big step towards looking at a much wider range of stars in the history of the universe.” She continues, mentioning that we’ll be able to “discover more stars like this” and compare them with the massive ones in the Milky Way.
Discovery of new massive stars will soon be easier with the James Webb Space Telescope when it will be launched in 2020. It will provide more power and it will have a better sensitivity, helping astronomers measure more details.