Overview
- The UC Irvine‑led paper published June 30 reports GJ 3378b as a confirmed super‑Earth about twice the mass of Earth in a roughly 21‑day orbit around a red dwarf about 25 light‑years away.
- Researchers calculate the planet receives about 90% of the starlight Earth gets from the Sun, placing it inside the star’s habitable zone where surface liquid water is possible under the right atmospheric conditions.
- The discovery and revised parameters come from radial‑velocity measurements made with instruments such as the Habitable‑zone Planet Finder at McDonald Observatory and the NEID spectrometer at WIYN, which give minimum mass and period but not radius or atmospheric composition.
- GJ 3378b’s atmosphere has not been detected and the planet lies near the so‑called cosmic shoreline, meaning stellar winds and radiation could have stripped a thin atmosphere and so habitability remains unresolved.
- The immediate priority is follow‑up by high‑contrast direct imaging and spectroscopy with next‑generation telescopes and future missions, a path also highlighted by comparisons to nearby candidates such as GJ 251 c that are being readied for the same observing tests.