In our Milky Way alone, 100 billion brown dwarfs exist: “failed” stars whose masses are insufficient for nuclear fusion of hydrogen to ignite inside them. Therefore they only shine weakly and are more difficult to observe than real stars. Megan Tannok of the University of Western Ontario and her colleagues succeeded in inspecting three special specimens of these brown dwarfs. As he writes in “Astronomical Journal” and in advance arxiv, Those samples rotate at their equator at speeds of about 100 kilometers per second – the highest value ever recorded in brown dwarfs and the maximum believed to be possible for such a protostar.
Three brown dwarfs only require between 1.08 and 1.23 hours for a full revolution. This is about a third faster than previous measurements. Tannok and co discovered the trio while they were evaluating data from the Spitzer Space Telescope. He then compared these with the values of two other telescopes. A comparison of the Earth shows how extreme the rotation speed is: at the equator, it rotates at a speed of about 1,650 kilometers per hour, while brown dwarfs rotate at a speed of 360,000 kilometers per hour.
The next fastest brown dwarf needs 1.4 hours for one revolution. And despite the intensive search, the group could not find any other sample with the same speed. Tannock therefore suspects that his team may have discovered the maximum possible rotation speed. Because with the rotational speed, the speed of the centrifugal forces, which counteracts the force of gravity, also increases. At some point it can separate objects.
Another reason for one type of speed limit is that the three observed brown dwarfs are in various warm, old, and massive quantities. Yet they rotate at the same speed. So you can actually move forward on the edge of the physically possible.
However, this paradox is according to model calculations according to which such large and heavy brown dwarfs can grow 50 to 80 percent faster, the researchers wrote. Further studies reveal whether objects are slow samples or whether there are actually fast samples in space. High pressure inside brown dwarfs can cause a breaking effect: this ensures that hydrogen becomes a conductive metal, which in turn generates an electromagnetic field, which can then reduce speed. But so far this is only a speculation.