The international astronomical Union defines Brown dwarfs as balls of gas in space that are too small to be bona fide hydrogen burning stars, but large enough to burn deuterium which anything bigger than about 13 times. The mass of Jupiter can do because of this brown dwarfs are often called failed stars or super Jupiter’s however, there’s a major problem with this deuterium burning based definition. It doesn’t make any scientific sense first. Unlike how hydrogen Fusion is huge. Since it means you can shine brightly for millions or billions of years burning deuterium doesn’t power or effect an astronomical object in any particularly meaningful way, which is probably why you haven’t heard much about it. I mean, look at this density versus Mass plot hydrogen burning is a cut-off that clearly distinguishes stars from non hydrogen burning things. And then there’s this other cut off between gas giants and rocky planets, but deuterium burning doesn’t appear distinguishing at all. So it may seem like there’s no real distinction between things that are slightly too small to be Stars, which we call Brown Dwarfs. And gas giant planets that they’re all really the same kind of object. However, just because deuterium isn’t a good cut off doesn’t mean there aren’t other options. So let’s briefly list the features that do scientifically distinguish brown dwarf like objects from gas giant like objects and the caveat here some of these statements are still being debated within the astronomical Community, but for each one, there are at least some researchers arguing in favor of it one movement Brown dwarfs whether above or below the deuterium limit and stars appear to
Located and move in similar ways in loose clusters with other similar objects moving with roughly the same relative speeds planets on the other hand of move around stars or brown dwarfs in orbits and are much closer to the nearest star to formation Brown dwarfs and stars appear to follow the same distribution of masses suggesting. They form the same way, the gravitational collapse of a cloud of gas and dust planets appear to follow a different distribution of masses suggesting they form in their own way by accreting from the protocol. Planetary disc of gas and dust left over around a star or brown dwarf after it forms three metallicity the dust and gas left over from Star formation has higher concentrations of metal to the atmospheres of Giant Gas planets have elevated levels of metal Brown dwarfs on the other hand have around the same amount of metal as stars for the size of orbits protoplanetary disks around Stars typically don’t extend much farther than a few hundred times the distance between the Earth and the Sun so that’s about as far out as you
Planets, however, Brown dwarfs often orbit stars or other Brown dwarfs at significantly greater distances five mass ratio protoplanetary disks are pretty much never more than ten percent of the mass of their parent star. So a planet to Star Mass ratio is almost always less than 1 to 10. However, Brown dwarfs and stars regularly orbit in pairs with mass ratios much closer to one to one basically a lot of evidence points to two separate populations of objects things that form from gravitational. Occasionally collapsing clouds of gas and things that form from The Leftovers it appears in unfortunate coincidence that the overlap in these two populations is roughly at the mass where a deuterium burning becomes possible. I mean if we didn’t have any other good way to distinguish between brown dwarfs and planets sure deuterium burning might be a reasonable rule of thumb. It’s also possible as some researchers contend that there is no real clear way of distinguishing between brown dwarfs and giant planets and that they really do just exists on a spectrum but either way deuterium is more
A distraction so among those who think that the evidence suggests Brown dwarfs are different from giant planets what supposedly distinguishes them is how they formed their consequent behavior and their composition the claim is this planet. So no matter how big appeared to be the leftovers of star formation and brown dwarfs no matter how small appear to be failed Stars. They started off the same way Stars Dubai gravitationally collapsing from a cloud of dust but failed to capture enough Mass to burn hydrogen in the end. It doesn’t matter how badly Lee they failed that is it doesn’t matter if they also can’t burn deuterium what matters is that they aspired to be stars and fell short
Globe Eld 