Researchers have developed a computational technique that removes the glare of stars from images taken by the James Webb Space Telescope, making it possible to detect exoplanets that were previously hidden in the data. The method, called Physics-based Learning for Imaging Planets (FLIP), builds a digital twin of the telescope's Near Infrared Camera and uses machine-learning optimisation to model and subtract starlight, achieving sensitivity two to 15 times better than standard methods, according to a study published in Nature on November 4.
Researchers at Northwestern University and Caltech worked on the project, which addresses a challenge in astronomy: exoplanets are very faint compared with the stars they orbit, and even tiny imperfections in a telescope can make it difficult to separate their light. Outside our solar system, scientists estimate that billions of worlds exist in the Milky Way galaxy alone.
To overcome this, the team built a digital replica of JWST's NIRCam instrument. They then used computational methods to solve for millions of possible physical imperfections and other unknowns that could affect the data. By sorting out potential defects, they modelled the glare of a given star precisely enough to remove it from test images.
"Directly imaging exoplanets is incredibly challenging because even the tiniest imperfections in a telescope can make it difficult to separate the faint light of a planet from the overwhelming glare of its star," explains Caltech's Katie Bouman, a co-author of the paper. "What's exciting is that we're showing how computation can help overcome limitations of the telescope itself. By combining a physical model of the instrument with optimization techniques from machine learning, we have been able to remove starlight much more precisely, making it easier to detect faint exoplanets and even reveal one that was previously hidden in the JWST data."
Lead author Rodrigo Ferrer-Chavez, a graduate student at Northwestern University, said the iterative process of tweaking parameters made the star's glare disappear in unexpected ways. "It gets dimmer and very deformed until at the end you get a pretty clean image and, if you're lucky, there's a blob there, which is a glowing planet," he said. Co-author Jason Wang, also at Northwestern, noted the approach goes beyond the physical stability of the telescope itself. "We've now gone beyond the telescope stability limit for the first time with this new technique, and this new paradigm, I think, can be applied to every instrument that's trying to image exoplanets," he said.
The team plans to apply FLIP to other instruments, including NASA's Nancy Grace Roman Space Telescope and ground-based telescopes, and hopes it could help inform future missions such as NASA's planned Habitable Worlds Observatory, which would be the first telescope designed to search for signs of life on exoplanets.
Analysis
Why This Matters
- Enables detection of exoplanets that were previously invisible in existing JWST data, potentially expanding the catalogue of known worlds.
- Demonstrates that computational imaging can overcome physical limitations of telescopes, a paradigm shift for exoplanet research.
- Could accelerate the search for Earth-like planets and signs of life by making future missions like the Habitable Worlds Observatory more feasible.
Background
Exoplanets are planets beyond our solar system. The Milky Way alone is estimated to contain billions of them. Imaging them directly is extremely difficult because they are much fainter than the stars they orbit, and even nanometer-level instabilities in a telescope can obscure them. The James Webb Space Telescope, launched in 2021, is the most powerful space observatory ever built, but its instruments are still subject to physical imperfections. The new technique, FLIP, uses a digital twin of the telescope's camera and machine learning to model and subtract starlight, effectively going beyond the telescope's stability limit.
What to Watch
- Application of FLIP to data from the Nancy Grace Roman Space Telescope, which carries a coronagraph designed at Caltech.
- Whether the technique can be adapted for ground-based telescopes, which face additional atmospheric distortions.
- The impact on the design of the proposed Habitable Worlds Observatory, a future NASA mission intended to directly image Earth-like planets.
Checked
10 claims in this story checked against 1 source: 9 supported.
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- SupportedThe new technique strips starlight from JWST data to reveal hidden exoplanets.News from www.caltech.edu: “a team of researchers has developed a new way to remove starlight from telescope data to reveal exoplanets hiding amongst the bright flares.”
- SupportedFLIP achieves sensitivity up to 15 times greater than standard methods.News from www.caltech.edu: “Their method improves detections of known planets with a sensitivity two to 15 times superior to standard techniques.”
- Partly supportedThe study was published in Nature on November 4.News from www.caltech.edu: “a co-author of a Nature paper about the new method published online November 4.”
- SupportedKatie Bouman said direct imaging is challenging because telescope imperfections can make it hard to distinguish a planet’s faint light from its star’s glare.News from www.caltech.edu: “"Directly imaging exoplanets is incredibly challenging because even the tiniest imperfections in a telescope can make it difficult to separate the faint light of a planet from the overwhelming glare of its star,"”
- SupportedBouman said computation and machine-learning optimisation helped remove starlight more precisely and reveal an exoplanet previously hidden in JWST data.News from www.caltech.edu: “"By combining a physical model of the instrument with optimization techniques from machine learning, we have been able to remove starlight much more precisely, making it easier to detect faint exoplanets and even reveal one that was previously hidden in the JWST data."”
- SupportedLead author Rodrigo Ferrer-Chavez said the star’s glare gets dimmer and deformed until a clean image may show a glowing planet.News from www.caltech.edu: “"It gets dimmer and very deformed until at the end you get a pretty clean image and, if you're lucky, there's a blob there, which is a glowing planet."”
- SupportedCo-author Jason Wang said the technique went beyond the telescope stability limit for the first time and could apply to every instrument trying to image exoplanets.News from www.caltech.edu: “"We've now gone beyond the telescope stability limit for the first time with this new technique, and this new paradigm, I think, can be applied to every instrument that's trying to image exoplanets."”
- SupportedResearchers used computational methods to solve for millions of possible physical imperfections and other unknowns affecting the data.News from www.caltech.edu: “the researchers used computational methods to solve for millions of possible physical imperfections and other unknowns that could affect data collected by the actual telescope.”
- SupportedThe team plans to apply FLIP to the Roman Space Telescope and ground-based telescopes.News from www.caltech.edu: “The team plans to work on improving their FLIP technique and applying it to other instruments, including the Roman Space Telescope and ground-based telescopes.”
- SupportedThe team hopes FLIP could inform NASA’s planned Habitable Worlds Observatory, described as the first telescope designed to search for signs of life on exoplanets.News from www.caltech.edu: “They hope it could help inform future missions as well, such as NASA's planned Habitable Worlds Observatory (HWO), which would be the first telescope designed to search for signs of life on exoplanets.”