The star's discovery by the Hubble Space Telescope was only announced earlier this year.
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Earendel, the most distant known star in the universe,
was discovered by the Hubble Space Telescope earlier this year, but now the
James Webb Space Telescope has glimpsed it too. (Image credit: NASA/ESA/Space
Telescope Science Institute) |
The James Webb Space Telescope has caught a glimpse of
the most distant star known in the universe, which had been announced by
scientists using Webb's predecessor the Hubble Space Telescope only a few
months ago.
The star, named Earendel, after a character in J.R.R.
Tolkien's "Lord of the Rings" prequel "The Silmarillion,"
was discovered thanks to gravitational lensing in a Hubble Space Telescope deep
field image. The star, whose light took 12.9 billion light-years to reach
Earth, is so faint that it might be rather challenging to find it in the new
James Webb Space Telescope image, which was released on Twitter on Tuesday
(Aug. 2) by a group of astronomers using the account Cosmic Spring JWST(opens
in new tab).
The original Hubble image provides some guidance as to
where to look through the zoomed-in cut-out. Essentially, Earendel, is the tiny
whitish dot below a cluster of distant galaxies. By comparing the Hubble image
with that captured by Webb, you can find the elusive Earendel.
We’re excited to share the first JWST image of Earendel, the most distant star known in our universe, lensed and magnified by a massive galaxy cluster. It was observed Saturday by JWST program 2282. pic.twitter.com/YoZZKRsdzf
— Cosmic Spring JWST (@CosmicSprngJWST) August 2, 2022
"We're excited to share the first JWST image of
Earendel, the most distant star known in our universe, lensed and magnified by
a massive galaxy cluster," the Cosmic Spring astronomers wrote in the
tweet, noting that the observations occurred on Saturday (July 30).
The tweet refers to gravitational lensing, which is
nature's help for astronomers. The effect takes advantage of the fact that
extremely massive bodies, such as galaxy clusters or supermassive black holes,
bend light from objects behind them. When light passes by such a body, it
behaves as if it were passing through the lens of a telescope, becoming magnified,
albeit also distorted. Using gravitational lensing therefore extends the reach
of telescopes, such as Hubble and Webb, enabling them to see farther and in
greater detail.
Webb was designed to see the first galaxies that
sprung up in the young universe in the first hundreds of millions of years
following the dark ages after the Big Bang. Astronomers, however, thought that
it would not be possible to see individual stars of this first generation of
suns that formed at that time. But gravitational lensing might actually enable
them to see inside those early stellar groupings in detail.
"JWST was designed to study the first stars.
Until recently, we assumed that meant populations of stars within the first
galaxies," astronomers from the Space Telescope Science Institute in
Maryland, which operates Webb and Hubble, wrote in a recent paper(opens in new
tab) discussing the technique. "But in the past three years, three
individual strongly lensed stars have been discovered. This offers a new hope
of directly observing individual stars at cosmological distances with
JWST."
Earendel, also known under its proper name WHL0137-LS,
is located in the constellation of Cetus, but don't expect to see it if you
look up at the night sky — even gravitational lensing isn't that powerful.
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