A super-Neptune is a
planet that is more massive than the planet
Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...
. These planets are generally described as being around 5–7 times as large as Earth with estimated masses of 20–80 ; beyond this they are generally referred to as
gas giants. A planet falling within this mass range may also be referred to as a sub-Saturn.
There have been relatively few discoveries of planets of this kind. The mass gap between Neptune-like and
Jupiter-like planets is thought to exist because of "runaway
accretion
Accretion may refer to:
Science
* Accretion (astrophysics), the formation of planets and other bodies by collection of material through gravity
* Accretion (meteorology), the process by which water vapor in clouds forms water droplets around nucl ...
" occurring for
protoplanets of more than —once this mass threshold is crossed, they accumulate much additional mass (due to
gravity increasing with mass and the presence of material in an
accretion disk
An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is typically a star. Friction, uneven irradiance, magnetohydrodynamic effects, and other fo ...
) and grow into planets the size of Jupiter or
even larger.
[
Known examples include ]Kepler-101b
GSC 03549-02811 (sometimes referred to as TrES-2 A or TrES-2 parent star in reference to its exoplanet TrES-2b), also known as Kepler-1) is a yellow main-sequence star similar to the Sun. This star is located approximately 704 light-years ...
, HAT-P-11b, and K2-33b.
See also
* Super-Earth
References
Types of planet
*
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