Overview
- The planet, about four times Earth’s mass, completes an orbit every roughly 54 days around the red dwarf Gliese 251, located about 18 light-years away.
- Gliese 251c resides in the star’s Goldilocks zone, which could allow liquid water if the planet retains a suitable atmosphere.
- The detection combines two decades of radial‑velocity observations with fresh measurements from the Habitable‑Zone Planet Finder at McDonald Observatory.
- Researchers distinguished quasi‑periodic stellar activity from a true planetary signature to validate the signal.
- The study, published in The Astronomical Journal, identifies Gliese 251c as a leading candidate for Extremely Large Telescope–era searches for atmospheric biosignatures that researchers say could begin within the next few years.