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.[13] 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.[14]
Gliese 433 d, whose discovery was published in January 2020, is 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.[8][15]
Gliese 433 c orbits the furthest out from the star. As of 2020 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.[15]
A survey using the
Herschel Telescope found an
infrared excess around the star, indicating the presence of an orbiting
circumstellar disk. This feature is unresolved but the mean temperature of 30 K puts it somewhere within a 16 AU radius from the host star.[12]
^
abcdeHoudebine, E. R. (September 2010). "Observation and modelling of main-sequence star chromospheres - XIV. Rotation of dM1 stars". Monthly Notices of the Royal Astronomical Society. 407 (3): 1657–1673.
Bibcode:
2010MNRAS.407.1657H.
doi:
10.1111/j.1365-2966.2010.16827.x.
^
abSuárez Mascareño, A.; et al. (September 2015). "Rotation periods of late-type dwarf stars from time series high-resolution spectroscopy of chromospheric indicators". Monthly Notices of the Royal Astronomical Society. 452 (3): 2745–2756.
arXiv:1506.08039.
Bibcode:
2015MNRAS.452.2745S.
doi:
10.1093/mnras/stv1441.
S2CID119181646.