The James Webb Space Telescope has captured the first direct image of a distant exoplanet, a world beyond our Solar System.
Webb has returned several pictures of the exoplanet HIP
65426 b, a gas giant six to twelve times the mass of Jupiter located roughly
385 light years from Earth, using a range of instruments.
The findings are part of an ongoing investigation and have
not yet been peer-reviewed or published in a scientific journal, but Nasa
announced them in a blog post.
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The James Webb Space Telescope captured this image of the
exoplanet HIP 65426 b. (NASA) |
"This is a pivotal moment, not only for Webb but also
for astronomy in general," said Sasha Hinkley, associate professor of
physics and astronomy at the University of Exeter. She is the principal
scientist in an international team studying exoplanets.
HIP 65426 b was first discovered in 2017 by the European
Southern Observatory’s Very Large Telescope, in Chile, which viewed the
exoplanet in short wavelengths of infrared light; longer wavelengths of
infrared light are blocked by Earth’s atmosphere for ground-based telescopes.
Being space-based, Webb is able to access more of the infrared spectrum and see
more details in distant planets.
Webb’s images are not the first direct images of exoplanets,
as the Hubble Space Telescope has managed to take pictures of other alien
worlds, but it is not easy — the intense brightness of a planet’s nearby star
can hide the light coming from that exoplanet. The HIP 65426 b, for instance,
is 10,000 times less bright than its star.
But HIP 65426 b orbits its star at a distance 100 times
greater than the Earth does the Sun, which aided scientists in picking out the
planet in Webb’s images. Webb’s instruments are also equipped with
coronagraphs, devices that black out the disk of the distance star to reduce
the glare and make finding and focusing on an exoplanet a little easier.
“It was really impressive how well the Webb coronagraphs
worked to suppress the light of the host star,” Dr Hinkley said.
The images, taken with multiple filters and Webb’s
Near-infrared camera (Nircam) and Mid-infrared instrument (Miri), are just the
first among what scientists hope will be a long string of exoplanet images and
discoveries made possible by the new space telescope. The images come on the
heels of a new analysis of one of Webb’s first observations, a spectrum of
light from the exoplanet Wasp 39b, which revealed the presence of carbon
dioxide in an alien world’s atmosphere for the first time.
“I think what’s most exciting is that we’ve only just
begun,” University of California, Santa Cruz post-doctoral researcher Aarynn
Carter, who analyzed the new Webb images of HIP 65426 b, said in a statement.
“There are many more images of exoplanets to come that will shape our overall
understanding of their physics, chemistry, and formation. We may even discover
previously unknown planets, too.”