IIT-Kanpur Professor With International Astronomers Discover 'Super-Jupiter' Planet in Solar System

New Delhi: In a landmark discovery, an international team of astronomers, including Dr Prashant Pathak from IIT Kanpur, has discovered a giant planet orbiting a nearby star similar to the Sun. The planet, named Epsilon Indi Ab, is classified as a 'super-Jupiter' due to its mass, which is over six times that of Jupiter, making it the first directly imaged mature exoplanet close to Earth. This significant finding has been published in the prestigious journal, Nature.

Using the James Webb Space Telescope’s (JWST) Mid-InfraRed Instrument (MIRI), the team achieved a breakthrough in exoplanet observation by directly imaging Epsilon Indi Ab. This direct imaging technique marks a departure from traditional methods that infer a planet’s presence through gravitational effects or dimming starlight. The ability to observe the planet directly showcases JWST’s advanced capabilities in high sensitivity and infrared imaging.

Epsilon Indi Ab is located 12 light-years from Earth and is remarkably cold, with a temperature around -1°C (30°F). Its orbit around its star is immense, about 28 times the distance between Earth and the Sun. This discovery was led by Elisabeth Matthews from the Max Planck Institute for Astronomy, who noted, “Previous studies underestimated the planet's mass and orbital separation. With JWST, we could accurately determine these properties.”

"We were excited when we realised we had imaged this new planet”, said Elisabeth Matthews, a researcher at the Max Planck Institute for Astronomy in Heidelberg, Germany and the lead author of the research article. 

“To our surprise, the bright spot that appeared in our MIRI images did not match the position we were expecting for the planet”, ”Matthews points out. “Previous studies had correctly identified a planet in this system but underestimated mass and orbital separation”. With the help of the JWST, the team was able to set the record straight.    

"This discovery is a major milestone in exoplanet research and sets the stage for future discoveries, bringing us one step closer to uncovering the mysteries of planetary systems beyond our own," said Prof. Manindra Agrawal, Director, IIT Kanpur. 

Dr. Prashant Pathak, Assistant Professor, Dept. of Space, Planetary & Astronomical Sciences & Engineering (SPASE), IIT Kanpur and a key member of the research team, explained, "This discovery is exciting because it gives us a chance to learn more about planets that are very different from our own. The planet’s atmosphere appears to have an unusual composition that indicates a high metal content and a different carbon-to-oxygen ratio than we see on our own solar system planets. This opens up fascinating questions about its formation and evolution. By studying Eps Ind Ab and other nearby exoplanets, we hope to gain a deeper understanding of planetary formation, atmospheric composition, and the potential for life beyond our solar system.”

Previous attempts to study Epsilon Indi Ab using radial velocity measurements were unsuccessful due to its long orbital period of around 200 years. The team’s direct imaging approach, aided by JWST’s MIRI camera and a coronagraph to block starlight, enabled the detection of the planet’s faint light. This technique, akin to observing a solar eclipse, allowed astronomers to capture clear images of Epsilon Indi Ab.

The researchers aim to further study the planet’s climatology and chemical composition through spectral analysis. Thomas Henning, a co-author of the research, highlighted the future goals: "We hope to survey other nearby planetary systems to understand the formation and evolution of gas giants."

The team included researchers from renowned institutions worldwide, demonstrating a collaborative effort to advance our understanding of distant worlds and their potential for life.