The new planet, called 51 Eridani b, is the first exoplanet discovered by the Gemini Planet Imager, a new instrument operated by a collaboration headed by Bruce Macintosh, a professor of physics at Stanford University.
The planet is a million times fainter than its parent star and shows the strongest methane signature ever detected on an alien planet.
The results are published in the current issue of Science.
Standford explains:
The Gemini Planet Imager (GPI) was designed specifically for discovering and analysing faint, young planets orbiting bright stars. While NASA’s Kepler space observatory has discovered thousands of planets, it does so indirectly by detecting a loss of starlight as a planet passes in front of its star. GPI instead searches for light from the planet itself.
“To detect planets, Kepler sees their shadow,” said Macintosh. “The Gemini Planet Imager instead sees their glow, which we refer to as direct imaging.”
James Graham, professor at the University of California, Berkeley, a project scientist for GPI, says the latest find is exactly the kind of system envisioned when GPI was designed.
“51 Eri is one of the best stars for imaging young planets,” said co-author Eric Nielsen, a postdoctoral researcher at Stanford and the SETI Institute.
“It’s one of the very youngest stars this close to the Sun. 51 Eri was born 20 million years ago, 40 million years after the dinosaurs died out.”