About this world
Kepler-61 b is a sub-Neptune orbiting Kepler-61, an orange dwarf (type K7V) 1.09 thousand light-years from Earth. It is about 2.1 times the size of Earth. It completes an orbit every 59.9 days at 0.25 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.25).
Its equilibrium temperature is about 273 K (0 °C): too cold for liquid water on its surface. By the "cosmic shoreline", it has likely held on to an atmosphere. Its atmosphere has already been studied: 2 spectroscopic observations.
It was discovered in 2013 by transit with Kepler. A planet crosses its star and dims it by a tiny, periodic fraction.