PARIS: Astronomers announced on Wednesday they have discovered a massive planet orbiting a tiny star, a bizarre pairing that has stumped scientists.

Most of the stars across the Milky Way are small red dwarfs like TOI-6894, which has only 20 per cent the mass of our Sun.

It had not been thought possible that such puny, weak stars could provide the conditions needed to form and host huge planets. But an international team of astronomers have detected the unmistakable signature of a gas giant planet orbiting the undersized TOI-6894, according to a study in the journal Nature Astronomy.

This makes the star the smallest star yet known to host a gas giant. The planet has a slightly larger radius than Saturn, but only half its mass. It orbits its star in a little over three days.

With a slightly larger radius than Saturn, planet is only half its mass

The astronomers discovered the planet when searching through more than 91,000 low-mass red dwarfs observed by Nasa’s TESS space telescope. Its existence was then confirmed by ground-based telescopes, including Chile’s Very Large Telescope.

“The fact that this star hosts a giant planet has big implications for the total number of giant planets we estimate exist in our galaxy,” study co-author Daniel Bayliss of the UK’s Warwick University said.

Another co-author, Vincent Van Eylen, of University College London, said it was an “intriguing discovery”.

“We don’t really understand how a star with so little mass can form such a massive planet!” he said. “This is one of the goals of the search for more exoplanets. By finding planetary systems different from our solar system, we can test our models and better understand how our own solar system formed.”

The James Webb space telescope is scheduled to turn its powerful gaze towards the planet next year to help uncover some more mysteries of this strange planet.

Published in Dawn, June 5th, 2025