A super-Earth-sized planet orbiting in or near the habitable zone around Sun-like star

TL;DR

This paper reports the discovery of Kepler-69c, a super-Earth-sized planet near the habitable zone of a Sun-like star, marking the smallest such planet found by Kepler in this region, advancing the search for Earth analogs.

Contribution

The paper presents the detection and confirmation of a super-Earth in or near the habitable zone of a Sun-like star using Kepler data and follow-up observations, highlighting its significance in exoplanet research.

Findings

Kepler-69c has a radius of approximately 1.7 Earth radii.

Orbital period of Kepler-69c is about 242.5 days.

Estimated equilibrium temperature of Kepler-69c is around 299 K.

Abstract

We present the discovery of a super-earth-sized planet in or near the habitable zone of a sun-like star. The host is Kepler-69, a 13.7 mag G4V-type star. We detect two periodic sets of transit signals in the three-year flux time series of Kepler-69, obtained with the Kepler spacecraft. Using the very high precision Kepler photometry, and follow-up observations, our confidence that these signals represent planetary transits is >99.1%. The inner planet, Kepler-69b, has a radius of 2.24+/-0.4 Rearth and orbits the host star every 13.7 days. The outer planet, Kepler-69c, is a super-Earth-size object with a radius of 1.7+/-0.3 Rearth and an orbital period of 242.5 days. Assuming an Earth-like Bond albedo, Kepler-69c has an equilibrium temperature of 299 +/- 19 K, which places the planet close to the habitable zone around the host star. This is the smallest planet found by Kepler to be orbiting in or near habitable zone of a Sun-like star and represents an important step on the path to finding the first true Earth analog.