Gliese 3021 b, also known as GJ 3021 b or HD 1237 b, is an
extrasolar planet approximately 57
light-year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
s away, orbiting its bright
G-dwarf parent star in the Southern
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the e ...
of
Hydrus. It was discovered with the Swiss
Euler Telescope at the Chilean
La Silla Observatory in 2000.
As determined by
doppler spectroscopy, the
jovian planet has an elongated orbit about 0.5
AU from its host star and a minimum mass 3.37 times that of Jupiter. Its orbital period of more than 133 days is much longer than that for typical
hot Jupiter
Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere temp ...
s.
A study published in 2001 suggested that the usual inability to determine the
orbital inclination of an extrasolar planet through radial velocity measurement had caused this mass to be severely underestimated. The
astrometric
Astrometry is a branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. It provides the kinematics and physical origin of the Solar System and this galaxy, the Milky Way.
Histor ...
orbit gives an orbital inclination of 11.8° and a mass of 16 Jupiter masses, which would make the object a
brown dwarf. However, later analysis showed that Hipparcos was not sensitive enough to accurately determine astrometric orbits for substellar companions, which means the inclination (and hence the true mass) of the planet are still unknown.
References
External links
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{{DEFAULTSORT:Gliese 3021 b
Giant planets
Hydrus (constellation)
Exoplanets discovered in 2000
Exoplanets detected by radial velocity
3
3021