New Delhi, July 22 -- SAN DIEGO - The planet was always there. Finding it required looking differently.

Astronomers led by researchers at UC San Diego and the University of Edinburgh confirmed this week that a third planet orbits Beta Pictoris, a young star 63 light-years from Earth whose surrounding debris disk has made it one of the most studied planetary systems in modern astronomy. The planet, designated Beta Pictoris d, was not detected by direct imaging. The James Webb Space Telescope found it by reading the carbon monoxide absorption lines in its atmosphere, a method that had never before been used to confirm an exoplanet's existence from the ground up.

The distinction matters because Beta Pictoris d was hiding inside one of the ...