UC Berkeley researchers discover farthest star ever observed, 9 billion light years away

March 25, 2019

The most distant star ever observed — at a distance of about nine billion light years — was captured using the Hubble Space Telescope by a group of researchers, including members of the UC Berkeley department of astronomy.

The star, named MACS J1149 Lensed Star 1, or LS1, was observed in April 2016 when researchers were examining images of a distant supernova, according to campus astronomy professor Alex Filippenko.

“For the first time ever we’re seeing an individual normal star — not a supernova, not a gamma ray burst, but a single stable star — at a distance of nine billion light years,” Filippenko said in a press release Monday.

Patrick Kelly, study leader and assistant astronomy professor at the University of Minnesota, Twin Cities, said he noticed there was a new source in the image and put together a large team to figure out what it was.

The star would not have been visible under normal circumstances because it is difficult to distinguish individual stars in distant galaxies beyond 100 million light years, but the position of this galaxy allowed for the viewing of the star, according to Kelly.

The effects of gravitational lensing — the bending of light by galaxy clusters in the line of sight — can magnify the distant universe and make faraway objects visible, according to the press release. Filippenko said in an email that this particular star was magnified by a factor of at least 2,000, making it visible in the telescope.

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