[Rod_Cloutier]

It was announced this week that a faint object in the Ort cloud could be a brown dwarf star in orbit around the sun, making our star system a binary system:

http://phys.org/news/2015-12-discovery- ... solar.html
https://youtu.be/F5oDY_hwcLw

A major announcement, however many are waiting for the peer reviewed articles to come out in another year or two about it. Certainly a good year for astronomy in 2015, first the Pluto 'Heart' and now a brown dwarf star orbiting Sol in the Ort cloud.

Not much to discuss here, just an interesting FYI

[Tanada]

It would be fascinating if the one object is a brown dwarf. Depending on its reading with the all sky infrared telescope http://sci.esa.int/astrophysics/55873-a ... -released/ they will be able to determine if either object is a brown dwarf, and from its spectrum which type (L or T). If it is a binary companion it will be the same age as Sol, around 4.6 Billion years old, and still pretty warm on the surface making it shine in the infrared telescope image if it can be verified.

Once the nature of the objects is determined careful observation will be needed to determine orbit parameters. If they are actually Brown Dwarf size and moving through the Oort cloud they could be the trigger for the Early and Late periods of heavy comet bombardments in the inner solar system.

http://www.bbc.co.uk/science/earth/eart ... ombardment

[Keith_McClary]

It was announced this week that a faint object in the Ort cloud could be a brown dwarf star in orbit around the sun, making our star system a binary system:

http://phys.org/news/2015-12-discovery- ... solar.html
https://youtu.be/F5oDY_hwcLw

Pretty cool star:

The obvious question then is, what is its nature and why has
it escaped earlier detection? Is it always too close to the binary?
Is it too cold? In that case, i.e., at temperatures below a hundred
Kelvin or so, the non-detection at shorter wavelengths, with e.g.
WISE, would be reconcilable.
http://arxiv.org/pdf/1512.02652v1.pdf

[Sixstrings]

The Overlords. They have come! Prepare a virgin for sacrifice. Bring out Trump!

Make the galaxy great again!

Hm, on topic to this thread..

These brown dwarfs, L dwarfs, y dwarfs etc. are a fascinating spectrum of almost-stars that would need more mass added to really kick up with fusion and become a star.

So they are like half and half things, somewhere in between a planet and a star.

There's varying degrees of fusion in them. A "star" would be fusing hydrogen. If I recall, a definition of a brown dwarf is that it doesn't fuse lithium.

If I understand it all correctly, it depends on total mass, the bigger something is then the more elements it would be fusing.

If there's a brown dwarf in the oort cloud and it's not fusing much of anything then that wouldn't really be a star -- I don't think a brown dwarf in a system counts as a binary system.

[Sixstrings]

Pretty cool star:

A brown dwarf isn't a star:

Brown dwarfs are objects which are too large to be called planets and too small to be stars. They have masses that range between twice the mass of Jupiter and the lower mass limit for nuclear reactions (0.08 times the mass of our sun).
https://www.google.com/?gws_rd=ssl#q=is+a+brown+dwarf+a+star

A star is a luminous sphere of plasma held together by its own gravity.
https://en.wikipedia.org/wiki/Star

A brown dwarf is not a "luminious sphere of plasma," therefore it is not a star.

There should be a word for this, something that's obviously not a star but yet is big enough to be fusing some elements. I guess that word is "brown dwarf," but then there are y dwarfs and such too and a whole spectrum.

Anyhow, "brown dwarf" isn't a star, so this wouldn't make Sol a binary system.

These objects in the Oort field are fascinating though. It's still big news, if that's a brown dwarf.

[AgentR11]

Think of the gravity assist you could get off something that massive, very dense, and yet cold enough to skim very deep into its gravity well.

To me, just spit-balling of course, if its really there, it makes the presence of comets in our current solar system much more reasonable. Its always kinda bugged me that objects that are as temporary as comets seem so plentiful, regularly travelling inside our own orbit. Something heavy has to be out there flinging them in from time to time. So a brown dwarf does the job, punts a big chunk of ice&muck inbound, saturn/jupiter pick it up and either eat it, shred it, or put it in an orbit that gives us another Bob the Comet for a few million years until the sun burns its mass away.

That'll be really cool if that is what's going on.

[Sixstrings]

Just to add some info, comparison of Jupiter to a brown dwarf, to a low mass star, and then the sun:



I'm noticing that some call brown dwarfs "stars." Is there anything definitive about this? From what I can find there's a classification of "sub stellar objects," is that the correct term?

Brown dwarfs are substellar objects not massive enough to sustain hydrogen-1 fusion reactions in their cores, unlike main-sequence stars. They occupy the mass range between the heaviest gas giants and the lightest stars, with an upper limit around 75[1] to 80 Jupiter masses (MJ). Brown dwarfs heavier than about 13 MJ are thought to fuse deuterium and those above ~65 MJ, fuse lithium as well.
https://en.wikipedia.org/wiki/Brown_dwarf

[Sixstrings]

Think of the gravity assist you could get off something that massive, very dense, and yet cold enough to skim very deep into its gravity well.

To me, just spit-balling of course, if its really there, it makes the presence of comets in our current solar system much more reasonable. Its always kinda bugged me that objects that are as temporary as comets seem so plentiful, regularly travelling inside our own orbit. Something heavy has to be out there flinging them in from time to time. So a brown dwarf does the job, punts a big chunk of ice&muck inbound, saturn/jupiter pick it up and either eat it, shred it, or put it in an orbit that gives us another Bob the Comet for a few million years until the sun burns its mass away.

That'll be really cool if that is what's going on.

Gravity assist: yep it would be good for that, although something like jupiter is big enough. You just have a satellite keep doing a burn on every periapsis pass and that makes the apoapsis envelope ever larger. Keep doing burns like that at the peri, then the apo escapes the sphere of influence after x number of go arounds.

Your point on a brown dwarf pulling comets in -- makes sense to me, maybe we get more comets than other systems do.

Anyhow, there's nothing definitive about this yet. Could turn out to be a large asteroid, or a blip, as the article says.

[AgentR11]

I was thinking more of fly-by assist to exit the solar system with better velocity, not orbital.

[Tanada]

Young Brown Dwarf objects are quite luminous, and as Six's link points out there are three Fusion thresholds between a planet like Jupiter and the smallest simple Hydrogen burning stars. Pause a moment and think about that, if Jupiter had been 13 times bigger it would have spent its first billion years shining with fusion of Deuterium in its core. Deuterium aka heavy hydrogen, is only 1 in 6,000 atoms of all hydrogen in our solar system so it would burn up this fuel over a few million to a billion years and then just be glowing with residual heat. The bigger it was the hotter it would burn and the faster it would use up its Deuterium fuel. Further up the scale it would fuse Lithium as well but still not be able to sustain light hydrogen fusion. In that case it would glow even brighter and because of its mass throw even more Oort cloud comets into the inner solar system.

The other thing to keep in mind even if it is not actively fusing anything today a Brown Dwarf still acts like a giant vacuum cleaner, as it passes through space any dust, gas or larger chunks of matter it encounters are either disturbed or pulled right in crashing into the top of the gas layer and releasing tremendous quantities of heat. As far as heat goes even now Jupiter itself is radiating twice as much heat from its cloud tops as it absorbs from the sun because it still has heat from its gravitational collapse and objects like Shoemaker-Levy 9 that it has been collecting into itself for the last 4.5 Billion years.

[PrestonSturges]

There's a lot of New Age BS associated with the idea, but people have kicked around the idea of "Nemesis" or "Planet X" for some time. Nemesis is more scientific, Planet X is more doomsday silly.

https://en.wikipedia.org/wiki/Nemesis_( ... tical_star)

Nemesis is a hypothetical red dwarf[1] or brown dwarf,[2] originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years),[2] somewhat beyond the Oort cloud, to explain a perceived cycle of mass extinctions in the geological record, which seem to occur more often at intervals of 26 million years.[2][3] As of 2012, over 1800 brown dwarfs have been identified and none of them are inside the Solar System.[4] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf.[5] The majority of solar-type stars are single.[6]

The BS part is the 1950 book “Planets In Collision "by Immanual Velikovsky, a Russian psychiatrist with a keen interest in the Bible.

[Tanada]

There's a lot of New Age BS associated with the idea, but people have kicked around the idea of "Nemesis" or "Planet X" for some time. Nemesis is more scientific, Planet X is more doomsday silly.

https://en.wikipedia.org/wiki/Nemesis_( ... tical_star)

Nemesis is a hypothetical red dwarf[1] or brown dwarf,[2] originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years),[2] somewhat beyond the Oort cloud, to explain a perceived cycle of mass extinctions in the geological record, which seem to occur more often at intervals of 26 million years.[2][3] As of 2012, over 1800 brown dwarfs have been identified and none of them are inside the Solar System.[4] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf.[5] The majority of solar-type stars are single.[6]

The BS part is the 1950 book “Planets In Collision "by Immanual Velikovsky, a Russian psychiatrist with a keen interest in the Bible.

Wasn't Velikovsky the guy who claimed that the middle east oil fields were the remnants of a hydrocarbon rich comet that crashed there around 1000 BC? Really whack job theories whomever it was, but sadly a lot of people will buy into any theory if you speak authoritatively and seem to know what you are talking about.

[ROCKMAN]

A couple of things I've learned. First, twin star systems are the norm...single star system are less common. And brown dwarfs, by definition, are not "stars":

"In order to understand what is a brown dwarf, we need to understand the difference between a star and a planet. It is not easy to tell a star from a planet when you look up at the night sky with your eyes. However, the two kinds of objects look very different to an astronomer using a telescope or spectroscope. Planets shine by reflected light; stars shine by producing their own light. So what makes some objects shine by themselves and other objects only reflect the light of some other body? That is the important difference to understand -- and it will allow us to understand brown dwarfs as well.

As a star forms from a cloud of contracting gas, the temperature in its center becomes so large that hydrogen begins to fuse into helium -- releasing an enormous amount of energy which causes the star to begin shining under its own power. A planet forms from small particles of dust left over from the formation of a star. These particles collide and stick together. There is never enough temperature to cause particles to fuse and release energy. In other words, a planet is not hot enough or heavy enough to produce its own light.

Brown dwarfs are objects which have a size between that of a giant planet like Jupiter and that of a small star. In fact, most astronomers would classify any object with between 15 times the mass of Jupiter and 75 times the mass of Jupiter to be a brown dwarf. Given that range of masses, the object would not have been able to sustain the fusion of hydrogen like a regular star; thus, many scientists have dubbed brown dwarfs as "failed stars". Starting in 1995, astronomers have been able to detect a few nearby brown dwarfs. All of the brown dwarfs discovered so far are parts of a binary system. A binary system is one in which two stars orbit around one another (just like the planets of our solar system orbit our star, the Sun). So why would we care about brown dwarfs? It is possible that a great deal of the mass in the universe is in the form of brown dwarfs, and since they do not give off much light, they could constitute part of the "missing mass" problem faced by cosmology."

[Outcast_Searcher]

Things like this remind me of the amazing amount of evolution in our scientific knowledge and our perspective on what we consider to be scientific reality, over time.

When I went to public school in '65 through '77, I was a good student and very into science. However, terms like Kuiper Belt, Oort Cloud, and Brown Dwarf never came up in our books or classes (I would have been FASCINATED, and remembered).

We were told that aside from comets, which were known to swing "way out there" in the cold part of their orbits, there wasn't anything known beyond the "planet" Pluto (about 30 AU from the sun) that was considered part of the solar system (rumors of a possible "Planet X", etc. excepted). Now the radius of the Oort cloud is surmised to be about 100,000 AU. That's well over a light year, by my math.

For me, fascination with outer space is the one constant.

https://en.wikipedia.org/wiki/Oort_cloud

[Cog]

There is no brown dwarf star out there. The article is derp. We would have already detected the gravity perturbations from it. There is something there but it ain't no dead star. Not enough mass.

[fleance]

There is no clear studies whether that object is brown dwarf or asteroid. However, it looks like asteroid.

[Sixstrings]

There is no brown dwarf star out there. The article is derp. We would have already detected the gravity perturbations from it. There is something there but it ain't no dead star. Not enough mass.

What do you mean by gravity perturbations? If it's a brown dwarf, or whatever it is, it's already been there for a very long time. The orbits of everything else has already settled (pretty much). Though if it is a brown dwarf, or super earth sized object, it could fling stuff inward that's passing by.

I don't think it's derp, Cog. From what I can tell these were legit astronomers, a Swedish team and a Mexican team.

There's LOTS of stuff out there. The oort cloud is full of stuff:



For all we know there could be not only one brown dwarf, but several.

When astronomers point a telescope up and see something -- they first have to determine how far away the thing is. This thing just happens to be close, in astronomical terms.

[Sixstrings]

There is no clear studies whether that object is brown dwarf or asteroid. However, it looks like asteroid.

Did I misunderstand all this? I thought they did something already to figure out that it's "super earth" sized? If that hasn't been determined yet, then yeah, there's no reason to speculate it's a brown dwarf.

But an asteroid would not be "super earth" sized -- something that big, is a PLANET. Or brown dwarf.. if there's any fusion going on..

[Subjectivist]

There is no clear studies whether that object is brown dwarf or asteroid. However, it looks like asteroid.

Did I misunderstand all this? I thought they did something already to figure out that it's "super earth" sized? If that hasn't been determined yet, then yeah, there's no reason to speculate it's a brown dwarf.

But an asteroid would not be "super earth" sized -- something that big, is a PLANET. Or brown dwarf.. if there's any fusion going on..

The link talks about two different objects, one that could be an asteroid and a different one that could be a brown dwarf.

Home Astronomy & Space Astronomy December 11, 2015
(Phys.org)—Two separate teams of researchers (one from Mexico, the other Sweden), have incited skepticism among the astronomy community by posting papers on the preprint server arXiv each describing a different large object they observed in the outer edges of the solar system. Both teams made their observations after reviewing data from ALMA—a cluster of radio dishes in the Chilean mountains.