Gliese 433


Gliese 433 is a dim red dwarf star in the constellation of Hydra, roughly 29.5 light years away from the Sun. Astronomers have announced the discovery of a super-Earth extrasolar planet in close orbit.

Planetary system

Gliese 433 b is an extrasolar planet which orbits the star Gliese 433. This planet is a super-Earth with at least six times the mass of Earth and takes approximately seven days to orbit the star at a semimajor axis of approximately 0.056 AU. The planet was announced in a press release in October 2009, but no discovery paper at the time was made available. A study described in a 2014 paper by Tuomi et al. confirmed both Gliese 433 b and another candidate planet, previously detected in 2012, Gliese 433 c.
Gliese 433 d, whose discovery was published in January 2020, is very similar in mass to Gliese 433 b but orbits slightly further out, actually within the optimistic habitable zone of the star, but it is still too close to the star, and therefore too warm, to be inside the narrower boundaries of the conservative habitable zone.
Gliese 433 c orbits the furthest out from the star. To date it is the nearest, widest orbiting, and coldest Neptune-like planet yet detected. It is also notable in having an unusually eccentric orbit for a large planet so far from its parent single star and other planets.