Overview
- A peer‑reviewed paper in The Astronomical Journal reports a radial‑velocity detection built from more than 20 years of observations, combining HPF and NEID data with archival measurements.
- GJ 251 c has a roughly 54‑day orbit and a minimum mass near 3.8 times Earth’s, placing it in a plausibly rocky regime within its star’s temperate zone.
- Researchers refined the known inner planet GJ 251 b and then isolated a stronger 54‑day signal consistent with a second, more massive world.
- Activity‑mitigation and color‑dependent modeling were used to distinguish planetary signals from M‑dwarf stellar noise, and the team stresses that an atmosphere and any biosignatures remain undetected.
- Because the system lies about 18–20 light‑years away, the planet is considered one of the best Northern Hemisphere targets for future direct imaging and atmospheric studies with TMT, GMT, ELT and proposed space interferometers.