New and rare direct image of a brown dwarf (earthsky.org)
Last edited Fri Feb 26, 2021, 03:31 AM - Edit history (1)
Posted by Paul Scott Anderson in Space | January 11, 2021
Astronomers have obtained one of the best images yet of a brown dwarf, an object in a mass range midway between stars and planets. This brown dwarf – called HD 33632 Ab – lies 86 light-years from our sun.
Brown dwarfs are star-planet hybrids, falling somewhere between the masses of giant planets like Saturn and Jupiter, and the smallest stars. All the brown dwarfs we know are outside our own solar system, and they are very dim; their great distances and general dimness makes them hard to photograph directly. In December, though, astronomers using the Subaru Telescope and the Keck Observatory in Hawaii released a new direct image of a brown dwarf that’s one of the best yet obtained. The brown dwarf, called HD 33632 Ab, orbits a sun-like star, HD 33632 Aa, which is 86 light-years away from our solar system.
The new peer-reviewed paper detailing the discovery was published by the researchers in The Astrophysical Journal Letters on November 30, 2020.
By definition, brown dwarfs have between 13 and 80 times the mass of our solar system’s largest planet, Jupiter. That’s the mass range in which a form of thermonuclear fusion – a “burning” of deuterium, a rare element left over from the Big Bang – can occur in an object’s interior. HD 33632 Ab is about 46 times Jupiter’s mass. It orbits at about 20 astronomical units (Earth-sun distance units, aka AU) from its star. That’s similar to the distance from our sun to the planet Uranus.
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more: https://earthsky.org/space/new-brown-dwarf-direct-image-hd-33632-ab
OK, I realize it's old news, but I thought it was interesting.
