Scientists identified the three fastest-spinning brown dwarfs ever

Clocking the fastest-spinning brown dwarfs.

In a new study appearing in the Astronomical Journal, scientists reported the three fastest-spinning brown dwarfs ever found. The discovery was made using data from NASA‘s Spitzer Space Telescope.

In the study, scientists made new speed measurements of these quasars. They also argued that these three rapid rotators could be approaching a spin speed limit for all brown dwarfs, beyond which they would break apart.

These speeding rotating stars’ diameter is the same as Jupiter but between 40 and 70 times more massive. They each rotate about once per hour, while the next-fastest known brown dwarfs rotate about once every 1.4 hours, and Jupiter spins once every 10 hours.

Given their size, that implies the largest of the three brown dwarfs whips around at more than 60 miles each second (100 kilometers each second) or about 220,000 miles each hour (360,000 kilometers each hour).

Wat surprised scientists so much that these fastest brown dwarfs have almost the same spin rate as each other. 

This can’t be ascribed to the brown dwarfs having framed together or being at a similar stage in their development since they are unique: One is a warm brown dwarf, one is cold, and the other falls between them. Since brown dwarfs excellent as they age, the temperature contrasts propose these brown dwarfs are of various ages.

The rotation of thethe objects generates centripetal force, threaten to throw riders from their seats; in stars and planets. To te surprise, it can tear the thing apart.

Before being apart, it will often start bulging around its midsection as it deforms under pressure. This is known as an oblation.

Based on the known characteristics of the brown dwarfs, they likely have similar degrees of oblation.

Megan Tannock, a Ph.D. candidate at Western University in London, Ontario, said“It would be pretty spectacular to find a brown dwarf rotating so fast it is tossing its atmosphere out into space. But so far, we haven’t seen such a thing. I think that must mean that either something is slowing the brown dwarfs down before they hit that extreme or that they can’t get that fast in the first place. The result of our paper supports some limit on the rotation rate, but we’re not sure of the reason yet.”

Journal Reference:
  1. Weather on Other Worlds. V. The Three Most Rapidly Rotating Ultra-Cool Dwarfs, arXiv:2103.01990 [astro-ph.SR]

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