Sub-Jupiter, also known as subjovian planet or saturnian planet, is a classification of planet with mass ranging from 0.1 to 0.5 Jupiter masses or approximately 31.8 to 158.9 Earth masses. Hence it is the third most massive mass class of planet, sub-Jupiter is rated M-Class III and has the symbol Jc.
Sub-Jupiters are gaseous with no solid surface, but there is a rocky core surrounded by liquid hydrogen-helium mixtures in their mantles. The atmospheres would contain one to several featured storms. Sub-Jupiters orbiting closer to their stars would have more violent storms and stronger winds than those orbiting further out. Their radius can range from 0.5 RJ to 1.3 RJ depending on composition and heat distribution.
There are an estimated 65 billion sub-Jupiters in our galaxy alone, making it the third least abundant mass class of planet after super-Jupiter and mid-Jupiter. This corresponds that 79‰ of all 820 billion planets in our galaxy are sub-Jupiters.
Known sub-Jupiters Edit
Saturn, massing 0.3 MJ, is the only sub-Jupiter in our solar system. There are a gross of extrasolar sub-Jupiters identified. HD 46375 b (Dejanira) and 79 Ceti b (Odysseus) were the first sub-Jupiter exoplanets identified, based on their speculative true masses. Other examples are HD 164922 b (Diomedes) and 55 Cancri f (Stygne).