Brown Dwarfs are heavenly bodies, neither small enough to be planets, nor large enough to be stars. Typically 5-90 times the mass of Jupiter (∼ 0.01 of the mass of our Sun), Brown Dwarfs have a gaesous composition of Hydrogen and Helium (just like the Sun), but the fusion nuclear reactions (that power the Sun) have not happened due to the relatively low temperature and pressure at the core.
Now for the first time, astronomers have observed a jet of matter spewing from a Brown Dwarf. This suggests that they form in a similar manner as stars, and even large planets like Jupiter and Saturn might have once spewed such jets.

Brown Dwarf Jet Source (Courtesy: NewScientistSpace)There are different theories to Brown Dwarf birth. Some think they condense from gas and dust clouds like other stars but are simply limited by the size of the clouds. Others say they are tossed out of their birth clouds prematurely by gravitational tussles with other growing stars in the cloud. Recent observations of large, dusty discs around brown dwarfs have bolstered the former theory, as only small - if any - discs are thought to be able to survive a violent ejection in the latter scenario.
Researchers led by Emma Whelan of Ireland's Dublin Institute for Advanced Studies (DIAS) have observed a jet stretching 1.5 billion kms (Earth to Sun distance, in comparison is 150 million kms!) from a young Brown Dwarf in a stellar nursery called Rho Ophiuchi. Similar jets have been detected around young, massive stars and are thought to form from material in the disc that swirls around them. The stars grow when matter falls on them from the disc, but the stars' magnetic fields funnel about a tenth of that matter back through the jets.
Jets can say a lot of things about the Brown Dwarfs. From the length and intensity of the jets, astronomers can detect the composition, mass, and magnetic properties of the Dwarf. In addition, such data can be used to determine if our Jupiter and Saturn sported such jets in the past, and if Saturnian Rings have anything to do with the creation of such jets.