Astronomers have discovered the most massive and "purest" known brown dwarf:
An international team of astronomers has identified a record breaking brown dwarf (a star too small for nuclear fusion) with the 'purest' composition and the highest mass yet known. The object, known as SDSS J0104+1535, is a member of the so-called halo -- the outermost reaches -- of our Galaxy, made up of the most ancient stars. The scientists report the discovery in Monthly Notices of the Royal Astronomical Society.
[...] Located 750 light years away in the constellation of Pisces, SDSS J0104+1535 is made of gas that is around 250 times purer than the Sun, so consists of more than 99.99% hydrogen and helium. Estimated to have formed about 10 billion years ago, measurements also suggest it has a mass equivalent to 90 times that of Jupiter, making it the most massive brown dwarf found to date. It was previously not known if brown dwarfs could form from such primordial gas, and the discovery points the way to a larger undiscovered population of extremely pure brown dwarfs from our Galaxy's ancient past.
Primeval very low-mass stars and brown dwarfs – II. The most metal-poor substellar object (open, DOI: 10.1093/mnras/stx350) (DX)
(Score: 1, Funny) by Anonymous Coward on Sunday March 26 2017, @06:38PM (1 child)
This isn't a euphemism, is it? Don't make look on Urban Dictionary.
(Score: -1, Troll) by Anonymous Coward on Sunday March 26 2017, @11:01PM
"Urban" is a euphemism.
(Score: 2, Interesting) by hendrikboom on Sunday March 26 2017, @07:16PM (5 children)
So we keep discovering more things out there that we didn't know about before. Is there any reason to think ordinary objects we just haven't seen yet might be all we need to explai the anomalous rotation rates of the outer reaches of galaxies? No need to postulate exotic new undiscovered particles?
(Score: 3, Funny) by requerdanos on Sunday March 26 2017, @07:52PM (2 children)
No need to postulate exotic new undiscovered particles?
As I understand it, no! Invisible "Dark Matter" explains all. Maybe that's why the star is brown; perhaps it's on its way to being "dark".
(Score: 1) by DmT on Sunday March 26 2017, @09:52PM (1 child)
Maybe its dark-brown.
(Score: 0) by Anonymous Coward on Sunday March 26 2017, @10:05PM
Ooooh it's one of *those*.
(Score: 5, Informative) by stormwyrm on Monday March 27 2017, @02:59AM (1 child)
In short, no [arxiv.org]. And ironically enough, the elemental composition of the brown dwarf from TFA might be evidence for the existence of these exotic new undiscovered particles. When the universe cooled down enough for the strong interaction to bind quarks into hadrons like protons and neutrons, these newly formed particles were hot enough to experience nuclear fusion and coalesce into bigger nuclei like deuterium, helium, and lithium in a process called primordial nucleosynthesis [wikipedia.org]. The relative abundances of these elements in primordial matter just like that brown dwarf is an important prediction of the theory of the Big Bang. The presence of dark matter makes one prediction on how much these ratios should be, which fit the current data we have available. Here’s a paper on this. [arxiv.org] The paper doesn’t give measurements of the elemental composition of the brown dwarf, though, but if someone were able to measure it, that’d be another piece of data to confirm or refute dark matter.
Numquam ponenda est pluralitas sine necessitate.
(Score: 2) by hendrikboom on Saturday April 01 2017, @12:56AM
Thanks for telling me about primordial nucleosynthesis. It is quite interesting.
-- hendrik
(Score: 2, Informative) by Anonymous Coward on Sunday March 26 2017, @11:48PM (2 children)
In case you were wondering (as I was)...
Smallest [ignited] Star [yet discovered] in the Universe [bellaonline.com]
-- OriginalOwner_ [soylentnews.org]
(Score: 2) by takyon on Monday March 27 2017, @02:28AM (1 child)
That should be about 83 Jupiter masses. Which means some brown dwarfs have larger masses than the smallest red dwarfs.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2, Informative) by laserfusion on Monday March 27 2017, @08:49PM
TRAPPIST-1 is also smaller than this brown dwarf, at 84 Jupiter masses [wikipedia.org].
The TFA says that the metallicity of a brown dwarf affects the minimum mass for hydrogen fusion. That's one reason for the overlap between brown dwarf and red dwarf sizes.
(Score: 2) by Phoenix666 on Monday March 27 2017, @01:36PM
I see you met my next-door neighbor Phil.
Washington DC delenda est.