Kepler-1652b

Lore & Background

Kepler-1652b was discovered via the transit method, where the planet blocks a tiny fraction of its host star's light as it passes between the star and Earth. Its radius of 1.60 R🜨 places it at the expected transition between rocky super-Earths and gaseous mini-Neptunes, suggesting it may be a small ice giant or ocean planet. The planet orbits its star every 38.1 days at an average distance of 0.1654 AU, and its eccentricity is believed to be near zero.

The host star, Kepler-1652, is a red dwarf with 0.404 times the mass and 0.382 times the radius of the Sun, a temperature of 3638 K, and an age of 3.2 billion years. It is about 1.6 to 2.6% as luminous as the Sun. Kepler-1652b receives about 81% of the sunlight Earth does, placing it well within the conservative habitable zone and making a runaway greenhouse effect unlikely. The planet is likely tidally locked, resulting in permanent day and night sides, though a thick atmosphere could distribute heat evenly.

Reader's Guide

Kepler-1652b's significance lies in its position within the habitable zone of a red dwarf star, a common type of star in the galaxy. Its equilibrium temperature of 268 K is similar to Earth's 255 K, and it receives 81% of Earth's sunlight, factors that support the possibility of liquid water on its surface. However, its large radius of 1.6 R🜨 places it at the threshold where planets are often expected to be either ocean worlds or mini-Neptunes, lacking a solid surface—a challenge for habitability. Additionally, red dwarfs like Kepler-1652 can produce strong flares that may erode a planet's atmosphere, though a strong magnetic field could offer protection. The planet's legacy is as a candidate for an eyeball planet, where one side is permanently illuminated and the other dark, and as a target for understanding the diversity of planets in the habitable zone. Its discovery and validation by Kepler highlight the ongoing effort to characterize potentially habitable worlds around low-mass stars.

Did You Know?

• Kepler-1652b has a radius 1.60 times that of Earth, placing it at the expected transition between rocky super-Earths and gaseous mini-Neptunes.
• Kepler-1652b is likely tidally locked, resulting in one side in permanent day and the other in permanent night.
• The host star Kepler-1652 is a red dwarf with an age of 3.2 billion years, compared to the Sun's 4.5 billion years.