James Webb telescope photographs exoplanet in unprecedented detail
A blazing gas giant beyond our solar system has been caught in unprecedented detail by the James Webb Space Telescope (JWST). This is the first image of an exoplanet by the $10 billion telescope. The remarkable image of HIP 65426 b, an object younger and hotter than Jupiter, has sent the world of astronomy into ecstasy. The planet is about 15-20 million years old.
Why does this story matter?
- Our search for a planet that is similar to Earth has been confined to the solar system. But not anymore.
- The image of an exoplanet captured by JWST gives us a glimpse of the future. It's not just an image.
- It also shows what the planet is like. With Webb's spectral analysis, we can look much farther than we ever looked for Earth's twin.
The exoplanet's mass is 6-12 times that of Jupiter
The HIP 65426 b is located 107 parsecs (around 355 light years) from Earth in the Centaurus constellation. It orbits around an A-type star and is around 100 times away from its host star than Earth is from the sun. It has a mass of about 6-12 times that of Jupiter. It was first discovered in 2017 by the Very Large Telescope in Chile.
What makes the image special?
Up until now, over 20 exoplanets have been imaged by Hubble Telescope and other ground-based telescopes. If so, what makes the image taken by JWST special? For starters, it is the first image of an exoplanet taken at deep infrared wavelengths. "It gives us wavelengths we've never seen planets at before," said Beth Miller, a member of the discovery team.
Why is direct imaging of exoplanets difficult?
The presence of exoplanets is usually inferred by indirect methods. However, taking direct images of exoplanets has proved to be a very challenging task. This is because host stars are a lot brighter than planets. The JWST makes this daunting task possible with coronographs in its Near Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI). This helps boost the contrast between the star and planets.
This is the first detection of exoplanet beyond 5 microns
The image of HIP 65426 b by JWST opens up a lot of possibilities for studying distant worlds. For the image, the team used mid- and thermal-infrared lights. They were able to detect the planet in all seven observational filters, making it the first detection of an exoplanet beyond five microns. They even made observations at 11.5 and 15.5 microns.
JWST will help in photographing even smaller exoplanets
The HIP 65426 b is 10,000 fainter than its star in near-infrared and a few thousand times fainter in mid-infrared. The image by JWST suggests that it will be able to capture even smaller planets. Sasha Hinkley, who led these observations, said "These observations confirm that JWST presents a powerful opportunity to characterize the population of exoplanets amenable to direct imaging in greater detail."
A transformative moment for astronomy: Hinkley
"This is a transformative moment, not only for Webb but also for astronomy generally," said Hinkley, associate professor of physics and astronomy at the University of Exeter. Aarynn Carter, who led the analysis of the images, said, "Obtaining this image felt like digging for space treasure." "I think what's most exciting is that we've only just begun," added Carter.