The exoplanet HIP 65426 b is a gas giant. The James Webb images give new details of its existence thanks to infrared.
Astronomers have used the James Webb Space Telescope for the first time to take a direct image of a planet outside the Solar System , NASA has reported .
The captured exoplanet is a gas giant, meaning it has no rocky surface and could not be habitable.
The image, viewed through four different light filters, shows how James Webb ‘s infrared gaze can easily capture worlds beyond the Solar System , pointing the way to future observations that will reveal more information about exoplanets than ever before.
“This is a transformative moment, not just for Webb but for astronomy in general,” said Sasha Hinkley, Associate Professor of Physics and Astronomy at the University of Exeter in the UK, who led these internationally collaborative observations.
Webb is an international mission led by NASA in collaboration with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
Meet HIP 65426 b
The exoplanet in Webb’s image, called HIP 65426 b, is between six and twelve times the mass of Jupiter, and these observations could help shrink it down even further. It is between 15 and 20 million years old, for the 4,500 million years of the Earth.
Astronomers discovered the planet in 2017 using the SPHERE instrument on the European Southern Observatory’s Very Large Telescope in Chile and imaged it using short infrared wavelengths of light. Webb’s view, at longer infrared wavelengths, reveals new details that ground-based telescopes could not detect due to the intrinsic infrared glow of Earth’s atmosphere.
The researchers have been analyzing the data from these observations and are preparing a paper that they will submit to journals for peer review. But Webb’s first capture of an exoplanet already hints at future possibilities for studying distant worlds.
Since HIP 65426 b is about 100 times farther from its host star than Earth is from the Sun, it is far enough from the star that Webb can easily separate planet from star in the image.
Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) are equipped with coronagraphs, which are sets of tiny masks that block starlight, allowing the telescope to take direct images of certain exoplanets such as East.
Further studies in the future
NASA’s Nancy Grace Roman Space Telescope , scheduled to launch later this decade, will demonstrate an even more advanced coronagraph. “It was really impressive how well Webb’s coronagraphs worked to suppress the light from the host star,” said Hinkley.
Taking direct images of exoplanets is challenging because stars are so much brighter than planets. Planet HIP 65426 b is more than 10,000 times fainter than its host star in the near infrared and a few thousand times fainter in the mid-infrared.
In each filter image, the planet appears as a slightly differently shaped patch of light. That’s because of the quirks of Webb’s optical system and how it translates light through different optics.
“Getting this image was like searching for space treasure,” said University of California postdoctoral researcher Aarynn Carter, who led the analysis of the images. “At first all I could see was the light from the star, but with careful image processing I was able to remove that light and discover the planet,” she added.
While this isn’t the first direct image of an exoplanet taken from space (the Hubble Space Telescope has captured direct images of exoplanets before), HIP 65426 b points the way forward for James Webb ‘s exoplanet exploration .
“I think the most exciting thing is that we are just getting started. 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 as well,” Carter concluded.