Earth-Size Planet Candidate Near Habitable Zone Reported From Kepler K2 Data

Overview

• Venner and colleagues announced HD 137010 b in The Astrophysical Journal Letters on Jan. 27, describing an Earth-size rocky planet candidate about 146–150 light-years away.
• The signal comes from a single 10-hour transit in archived Kepler K2 data, with modeling indicating an orbital period likely near one year.
• The host star is a cooler, dimmer K-dwarf, so the planet receives less than one-third of Earth’s sunlight, implying possible surface temperatures near −90°F (−68°C).
• Models place the candidate near the outer edge of the habitable zone, with about a 40% chance in the conservative zone and 51% in the optimistic one, yet roughly even odds it lies beyond habitability.
• The initial transit was flagged by volunteers in Oxford’s Planet Hunters project, and confirmation efforts may target future transits with TESS or ESA’s CHEOPS along with mass measurements via radial-velocity observations.