Astronomers identify purest, most massive brown dwarf

Astronomers identify purest, most massive brown dwarf
An artist's impression of the new pure and massive brown dwarf. Credit: John Pinfield.

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.

Brown dwarfs are intermediate between planets and fully-fledged stars. Their is too small for full of hydrogen to helium (with a consequent release of energy) to take place, but they are usually significantly more massive than planets.

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 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.

The research team was led by Dr ZengHua Zhang of the Institute of Astrophysics in the Canary Islands. He said: "We really didn't expect to see brown dwarfs that are this pure. Having found one though often suggests a much larger hitherto undiscovered population —I'd be very surprised if there aren't many more similar objects out there waiting to be found."

SDSS J0104+1535 has been classified as an L type ultra-subdwarf using its optical and near-infrared spectrum, measured using the European Southern Observatory's Very Large Telescope (VLT). This classification was based on a scheme very recently established by Dr Zhang.


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More information: Z. H. Zhang et al. Primeval very low-mass stars and brown dwarfs – II. The most metal-poor substellar object, Monthly Notices of the Royal Astronomical Society (2017). DOI: 10.1093/mnras/stx350
Citation: Astronomers identify purest, most massive brown dwarf (2017, March 24) retrieved 22 July 2019 from https://phys.org/news/2017-03-astronomers-purest-massive-brown-dwarf.html
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Mar 24, 2017
Well, given the surprise shown by the scientific community, I'd like to venture this theory:
If someone were ever to make a statistical analysis of all planets or stars discovered and studied so far, they'll likely find that ALL objects found are unique.
This is simply going by the reflection of what we find here on earth. The Creator made just about everything unique. Which of course also makes me wonder if that goes down to such minute things as atoms, electrons, protons and the like. Who knows at this stage?

Mar 24, 2017
If someone were ever to make a statistical analysis of all planets or stars discovered and studied so far, they'll likely find that ALL objects found are unique.

Sure.
makes me wonder if that goes down to such minute things as atoms, electrons, protons and the like.

Well but in that case we would have no fermions and bosons, it would be maxwellons all the way down.

Mar 25, 2017
You can't find 2 stars that are precisely identical. That's an event with an infinitesimal chance - or close to it anyway. If one were to find 2 such stars, he would probably think one of them is the reflection of the other in his telescope. Or something like that. So stars and planets would be unique. Elementary particles... they are probably unique, each one of them, if one considers the quantum fluctuations around the particle. Those, being fluctuations, would be different for any 2 particles.

In fact I wonder if there could be 2 identical objects out there. They should be simple enough so that the number of possible permutations is quite small. But then, quantum fluctuations would still appear, so the degrees of freedom would go to infinity. 2 electrons may seem identical (if they have the same spin), but they have electrical fields which would induce fluctuations nearby, so not good. 2 chairs wouldn't do, being composed of too many particles.

Mar 25, 2017
makes me wonder if that goes down to such minute things as atoms, electrons, protons and the like

You can always add properties until you get everything to be unique (just add position and/or momentum and every atom is then unique).

I think Asimov said it in one of his books (The Gods Themselves)...paraphrasing from memory here (and retranslating from the german translation):
"The number two makes no sense and cannot exist"

Either everything is unique or everything is one. Take your pick. Makes no difference either way.

Mar 26, 2017
Gotta be some fusion goin' on! That star was 'detected'! A plain cold solitary body at that distance and that size has not a snowball's chance in a hot place of gettin' found.

Mar 27, 2017
Osiris wrote: "Gotta be some fusion goin' on! That star was 'detected'! A plain cold solitary body at that distance and that size has not a snowball's chance in a hot place of gettin' found."

"Located 750 light years away in the constellation of Pisces," That's not really that far away. Any body that massive gives off heat from accretion that can last for a long time. Telescopes and detection instruments have advanced. A brown dwarf is much easier to detect when isolated compared to one orbiting a normal star. Perhaps gravitational lensing was involved in this detection?

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