Overview

• TOI-6894b has a radius slightly larger than Saturn but only about half its mass, making it one of the lowest-density gas giants discovered.
• The planet circles red dwarf TOI-6894, which at just 20% of the Sun’s mass is the smallest star known to host a transiting giant planet.
• With an atmospheric temperature near 420 Kelvin and transits that block 17% of its star’s light, TOI-6894b ranks among the coldest gas giants available for detailed study.
• Its existence around a low-mass star cannot be fully explained by core accretion theory, prompting consideration of alternative formation pathways such as gravitational disk instability.
• The discovery has been confirmed and TOI-6894b has been selected for James Webb Space Telescope follow-up to analyze its atmospheric composition and probe its formation history.