Overview
- A peer‑reviewed paper published on June 30, 2026, confirmed GJ 3378b as a planet using Doppler data and refined its orbit to about 21–21.5 days.
- The world is a super‑Earth roughly twice Earth’s size that sits about 25 light‑years away and receives roughly 90% of the starlight Earth gets from the Sun.
- Researchers detected GJ 3378b with high‑precision radial‑velocity instruments, notably the HPF spectrograph on the Hobby‑Eberly Telescope and the NEID spectrometer on the WIYN Telescope.
- The key unknown is whether the planet still has an atmosphere because it does not transit its star and its orbit places it near the ‘cosmic shoreline’ where red‑dwarf radiation can strip gases.
- Confirming an atmosphere and searching for biosignatures will rely on future high‑contrast direct imaging and spectroscopy from next‑generation observatories such as GMT, ELT, or NASA’s Habitable Worlds Observatory, making GJ 3378b a top long‑term target for habitability studies.