2020/04/01 by Andrew Vanderburg, Pamela Rowden, Steve Bryson +9 · 1 citation
Physics and Astronomy · #Stellar, planetary, and galactic studies #Astro and Planetary Science #Astronomy and Astrophysical Research
paper · pdf · doi:10.3847/2041-8213/ab84e5
openalex publication_date 2020/04/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract We report the discovery of an Earth-sized planet in the habitable zone of a low-mass star called Kepler-1649. The planet, Kepler-1649 c, is 1.06 times the size of Earth and transits its 0.1977 ± 0.0051 “mid” M-dwarf host star every 19.5 days. It receives 74% ± 3% the incident flux of Earth, giving it an equilibrium temperature of 234 ± 20 K and placing it firmly inside the circumstellar habitable zone. Kepler-1649 also hosts a previously known inner planet that orbits every 8.7 days and is roughly equivalent to Venus in size and incident flux. Kepler-1649 c was originally classified as a false positive (FP) by the Kepler pipeline, but was rescued as part of a systematic visual inspection of all automatically dispositioned Kepler FPs. This discovery highlights the value of human inspection of planet candidates even as automated techniques improve, and hints that terrestrial planets around mid to late M-dwarfs may be more common than those around more massive stars.