Kepler-69c – a Super-Earth Extrasolar Planet

Kepler-69c – a Super-Earth Extrasolar Planet

Kepler-69c is a super-Earth exoplanet in the habitable zone of a G-type star. It’s a verified super-Earth extrasolar planet, most likely rocky, circling the Sun-like star Kepler-69, the outermost of two identified by NASA’s Kepler probe. It has a mass of 3.57 Earths, takes 242.5 days to complete one orbit around its star, and is 0.64 AU away from it. It is approximately 2,430 light-years (746 parsecs) away from Earth.

Kepler-69c orbits its star at a distance of 0.64 AU (96,000,000 km; 59,000,000 mi) from its host star with an orbital period of around 242.46 days, has a mass at least 2.14x that of Earth, and a radius of approximately 1.7 times that of Earth. Initially, it was thought that Kepler-69c would be livable, but more recent research indicates that it is located outside of the habitable zone, and so is most likely to resemble the planet Venus, with temperatures and circumstances far too hot to host any life, rendering it inhospitable.

NASA reported the discovery of the exoplanet as part of the Kepler mission data release in April 2013. The transit method was used to discover the exoplanet, which measures the dimming effect caused by a planet as it passes in front of its star.

Mass, radius, and temperature

Kepler-69c is a super-Earth, an exoplanet with a bigger radius and mass than Earth but less than the ice giants Uranus and Neptune. It has an estimated equilibrium temperature of 325 K (52 °C; 125 °F), although it most likely has a far higher surface temperature of 548 K (275 °C; 527 °F). It has a radius of 1.71 REarth and an estimated mass of 2.14 MEarth. These properties make it similar to Venus, but it is more massive, hence it is referred to as a “super-Venus.”

Kepler-69c is a planet that, depending on how livable its surface is, might be a “super-Venus” or a “super-Earth.” However, at the time of its discovery, experts stated that the planet bore many characteristics to Earth and that it orbited a star comparable to our own sun.

Host star

The planet circles Kepler-69, a (G-type) star that is orbited by two planets. The star has a radius of 0.93 R☉ and a mass of 0.81 M☉. It has a surface temperature of 5638 K and an estimated age of 9.8 billion years, implying that it is reaching the end of its life. The Sun, on the other hand, is approximately 4.6 billion years old and has a surface temperature of 5778 K.

The apparent magnitude of the star, or how brilliant it seems to us from Earth, is 13.7. As a result, Kepler-69 is too dark to see with the naked eye.


Kepler-69c orbits its host star at a distance of 0.64 times that of Earth every 242 days, with around 80% of the Sun’s brightness. This is quite similar to the orbital period and distance of Venus in the Solar System.

Kepler-69c, an exoplanet around 2,700 light-years from Earth, was hailed as the most Earth-like alien planet when it was discovered. Since then, there has been some dispute regarding whether it is more like Venus or Earth. NASA, for example, highlighted that Kepler-69c’s orbit of 242 days is similar to Venus’s orbit in our solar system.