Y-Dwarf 1:1.5 billion

A representation of a class Y Brown Dwarf of about 13-30 times the mass of Jupiter.

Class Y dwarfs are a theoretical classificiation of Brown dwarf object with a surface temperature range of 600K and below, making them even colder than the T dwarfs. Recently discovered objects suspected to be of this type are in fact so cold, they'd be colder than the human body! 

Despite being many times the mass of Jupiter this failed star objects are often the same, or in fact, even smaller than our gas giant (they tend to become denser rather than bigger). 
​This one in particular is assumed to be 0.93 times Jupiter's radius.