Neptune-sized exoplanet is too big for its host star

Enlarge (credit: NASA/JPL-Caltech)

You win some, you lose some. Earlier this week, observations made by the Webb Space Telescope provided new data that supports what we thought we understood about planet formation. On Thursday, word came that astronomers spotted a large planet orbiting close to a tiny star—a star that's too small to have had enough material around it to form a planet that large.

This doesn't mean that the planet is "impossible." But it does mean that we...