Astronomers Discover Third-Closest Star System To Earth

The Bad Astronomer writes "Astronomers have found the third-closest star system to the Earth: called WISE 1049-5319, it's a binary brown dwarf system just 6.5 light years away. Brown dwarfs are faint, low mass objects 13 — 75 times the mass of Jupiter, and are so dim they are very difficult to detect. These newly-found nearby objects were seen in observations from 1978 but went unnoticed at the time, but since that date the large apparent motion of the binary made their proximity obvious. Only two star systems are closer: Alpha Centauri (4.3 light years) and Barnard's star (6 light years)."

Comments

These are the starts that are closest to me

[Anonymous Coward]

Sheldon's going to have to fix his song.

Re:These are the starts that are closest to me

[Dr. Sheldon Cooper]

I most certainly shall not. I don't consider a brown dwarf to be a real star. I generally don't spend time considering topics related to astronomy at all, as it is widely known that astronomy is a field for children or H1B imports with selective mutism and a penchant for broadway musicals.

To put it in terms you would be more likely to understand, if stars were thespians, a brown dwarf would be on par with Jean Claude Van Damme.

And before you ask, a thespian is what you normies call an actor.

If brown dwarfs can't sustain fusion

[mozumder]

then why are they considered stars?

Re:If brown dwarfs can't sustain fusion

[MyLongNickName]

I'm not sure why this is modded down. A brown dwarf never achieves sustained fusion and is not considered a full-fledged star, so i am also confused to why it is considered a star system.

Re:If brown dwarfs can't sustain fusion

[skade88]

According to the Brown Dwarf Wiki article "However, for some years now there has been debate concerning what criterion to use for defining the separation between a brown dwarf and a giant planet at very low brown dwarf masses (~13 Jupiter masses).[3] One school of thought is based on formation, and another on interior physics.[3] Dwarfs are categorized by spectral classification, with the major types being M, L, T, and Y.[3] Despite their name, most brown dwarfs would appear magenta to the human eye.[3] Another debate is whether brown dwarfs are required to have experienced fusion at some point in their history. Some planets are known to orbit brown dwarfs: 2M1207b, MOA-2007-BLG-192Lb, and 2MASS J044144b. Brown dwarfs may have fully convective surfaces and interiors, with no chemical differentiation by depth.[4]" http://en.wikipedia.org/wiki/Brown_dwarf

Re:If brown dwarfs can't sustain fusion

[MightyYar]

It's subject to some debate. Basically, mostly the differentiation between a gas giant and a small brown dwarf comes down to how it formed and the physics going on inside.

Re:If brown dwarfs can't sustain fusion

[skade88]

Dwarf planets and stars are sensitive and preferred it if you called them little planets and little stars.

Re:If brown dwarfs can't sustain fusion

[Waffle Iron]

The term "little" could be construed as demeaning.

I think the currently preferred term is "differently sized" planets.

Re:If brown dwarfs can't sustain fusion

[jc42]

I think if it is the center of a planetary system, then it is a star.

This is a nice example of why you need to be careful in how you define things. With the above definition, our own sun isn't a "star" (most of the time).

Isaac Newton was one of the people who pointed this out. The objects in our solar system actually orbit the barycenter of the system, the technical name for what is often called the center of mass (or more weirdly, the center of gravity). Because most of the solar system's mass outside the sun is Jupiter, and because Jupiter is far enough away from the sun, the barycenter of the solar system is usually outside the sun. Not far outside, true, but outside the visible "surface" of the sun. It's only inside the sun when most of the other big planets are on the other side from Jupiter.

So, technically speaking, Earth and the other planets don't actually orbit the sun; they orbit the barycenter, which is (usually) outside the sun. The sun itself also orbits the same barycenter, in a very close orbit. And a few humorous remarks have been made based on the fact that Newton actually demonstrated that the Earth doesn't revolve around the sun.

We probably need a better definition of the term "star" than "has planets". That also causes a different problem: It's a circular definition, since the common definition of a "planet" includes orbiting a star. So one might decide that Jupiter is a star, and at least its four major moons instantly become planets, which then is used in the definition of "star" to prove that Jupiter is indeed a star.

There's a lot of humor in the way such terms are being defined by various (mostly non-astronomical) parties. Maybe we should go back to the definition that a star is an astronomical thing that undergoes sustained nuclear fusion. Ya think that'd work?

(We do have to carefully word it so that the experimental fusion projects in Earthly labs don't qualify as stars. ;-)

Re:If brown dwarfs can't sustain fusion

[ls671]

I'm not sure why this is modded down.

Just click on the score, a pop-up should appear showing the post started at -1 and got +6 interesting , at the time I wrote this message.

So it was never modded down.

And where's the mass of the universe?

[sshambar]

Can someone explain to me how discovering the THIRD closes system to ours in 2013 doesn't suggest that all the Dark Matter(tm) that's out there just isn't a mass of brown dwarfs that we can't see, and not a whole new class of matter?

Re:And where's the mass of the universe?

[sshambar]

(obvious typo: that's closest)

Re:And where's the mass of the universe?

[skade88]

Interesting....The idea of dark matter is around because our models of the universe that are only based on what we can see don't measure up to the mass we figure the universe needs to actually have. My question to you is, how many extra brown dwarfs would we need to close that gap in mass?

Re:And where's the mass of the universe?

[Waffle Iron]

As I recall, it's because the orbital velocities of regular stars in disk-shaped galaxies suggest that dark matter is distributed spherically around the galactic center rather than concentrated in the disk. That implies that unlike brown dwarfs, dark matter interacts neither with normal matter nor itself by any force other than gravity.

Re:And where's the mass of the universe?

[Baloroth]

Can someone explain to me how discovering the THIRD closes system to ours in 2013 doesn't suggest that all the Dark Matter(tm) that's out there just isn't a mass of brown dwarfs that we can't see, and not a whole new class of matter?

Because of Big Bang nucleosynthesis. We can know how much baryonic matter ("normal" matter) there is in the universe by certain cosmological observations. Other cosmological observations show there is more matter out there than that (about 5 times more) and therefore it cannot all be brown dwarfs, black holes, or other dark but non-exotic forms of matter.

Re:And where's the mass of the universe?

[Kjella]

Apparently there's good reason to think it's not atoms at all:

A small proportion of dark matter may be baryonic dark matter: astronomical bodies, such as massive compact halo objects, that are composed of ordinary matter but which emit little or no electromagnetic radiation. Study of nucleosynthesis in the Big Bang produces an upper bound on the amount of baryonic matter in the universe, which indicates that the vast majority of dark matter in the universe cannot be baryons, and thus does not form atoms.

Of course they could be wrong, any models of what happened during the Big Bang are extreme extrapolations. Or it could be the single Big Bang theory that is wrong, that there's lots of old, dark matter from previous big bangs. But the most plausible theory seems to be something like massive neutrinos.

Re:And where's the mass of the universe?

[myrikhan]

IIRC there aren't enough of them and they're too low mass to make up the dark matter. After a bit of searching I found this thesis. It looks like a good introduction to the area.

http://arxiv.org/pdf/1110.2757

Re:And where's the mass of the universe?

[Charliemopps]

Because dark matter isn't dark because it doesn't give off light. It's dark because it doesn't even interact with normal matter in any other way than gravitation. We can see the effects of its mass, but it does not occlude stars behind it, the light and radio waves passes right through as if it didn't exist.

Re:And where's the mass of the universe?

[Hentes]

The problem with that is if gravitational anomalies indeed are caused by a form of invisible matter, then its mass would have to be far too great to consist of normal matter. There are many forms of possibly invisible matter: compact stars, neutrinos etc but their masses don't add up to even a fraction of the amount needed.

Re:And where's the mass of the universe?

[skids]

Well, the above explanations are all very educational. The computer programmer in me wants to answer using short circuit logic, however: we have always been able to see these particular stars. We just didn't know they were so close, because we were looking at still frames.

Re:And where's the mass of the universe?

[Waffle Iron]

No, it's the same gravity, which affects both normal matter and dark matter the same.

The difference is that if dark matter interacted by any force other than gravity (such as electromagnetism, etc.), then it would be deflected on encounters with other objects instead of passing right through them. This would eventually cause the dark matter to settle into a disk, like the rest of the stuff in the galaxy. However, it instead seems to remain in its initial spherical distribution to this day.

Re:And where's the mass of the universe?

[Attila Dimedici]

Yes, gravity is primarily what gives galaxies their shape. However, the gravitational effects of the matter which we can observe does not yield the structure that we observe and no other force seems to fill the bill. This suggests that there are objects out there which exert gravitational force but do not interact with any of the other forces we currently observe in the universe (in particular, electro-magnetic force since that is the only one, besides gravity, that acts over a range long enough to be reliably observed at the distances we are talking about).

Re:And where's the mass of the universe?

[femtobyte]

There are non-gravitational forces that are important on the galaxy formation scale --- specifically, collisions/drag from interstellar gas (on the micro scale, due to electromagnetic intermolecular interactions) is necessary to collapse a big gob of mass into a galactic disk. If all particles were like dark matter, only weakly or non-interacting except through gravity, then galactic disks would never form (you'd just have big, amorphous volumes of particles whizzing past each other).

Re:And where's the mass of the universe?

[painandgreed]

Interesting....The idea of dark matter is around because our models of the universe that are only based on what we can see don't measure up to the mass we figure the universe needs to actually have. My question to you is, how many extra brown dwarfs would we need to close that gap in mass?

Given similar brown dwarves would be about 1/50th of a solar mass and we have five stars (assuming one solar mass each) within 7 ly, we'd need to find 248 more brown dwarves like these within 7 ly to equal the amount of mass in the same area. To make up for the 5-6 times as much matter that dark matter is more than luminous matter, we'd have to find around 1500 such brown dwarves within 7 ly to go "oops, all dark matter is just normal matter after all". With an average density, that means there should be five such brown dwarves, averaging twenty times the size of Jupiter within a light year of our sun and ~370 closer to us than Alpha Centauri.

Unique names for nearby stars

[doconnor]

We should probably come up with unique names for the all the stars within 10 light years or so instead of calling them things like WISE 1049-5319 and Wolf 359. They are probably going to be of increasing importance in the coming decades and centuries as we are able to study them more closely.

Re:Unique names for nearby stars

[Zephyn]

Only if a certain percentage of their solar system's mass or above is made up of ethanol.

At least on the weekends....

Re:Unique names for nearby stars

[geekmux]

We should probably come up with unique names for the all the stars within 10 light years or so instead of calling them things like WISE 1049-5319 and Wolf 359. They are probably going to be of increasing importance in the coming decades and centuries as we are able to study them more closely.

Yes, if only we had a system that translated numbers into names that worked on a global scale that everyone would recognize(.com)...

Re:Proxima Centauri

[skade88]

Mod this up or edit the wiki article so Proxima Centauri is 14 light years away...

Can someone explain something to me?

[NoNonAlphaCharsHere]

I just don't understand the current astronomical obsession with nearby stars/solar systems and exoplanets. OK, I do understand that in this particular case, it's WISE data and simply fell into their laps while going through the survey data. But in the general case, from an astronomy/astrophysics interested layman's perspective, way way way too much intellectual bandwidth, funding, and future research proposals go into the search for exoplanets. I mean, here we are, postulating "dark matter" and "dark energy" to explain why the universe doesn't match our models, and yet we're spending all this time and money on looking for (mostly Jupiter-sized or bigger) planets that don't really tell us anything useful.

And don't even get me started on the Standard Model, with it's 27 Magic Constants; which I think is part and parcel of the whole dark matter/energy problem. Sure, the Standard Model has lots of predictive/descriptive power, but absolutely ZERO explanatory power.

I'm not trolling here, I really don't understand it and really want to know: what's the strange obsession with exoplanets, and what do we learn besides simply cataloging them?

Re:Can someone explain something to me?

[osu-neko]

The premise behind your question is the fallacy of the convertibility of human time and resources, as if we're all interchangeable and equally qualified to participate in any task. Let me put it this way: how much further would we get into understanding the Standard Model if the millions of people playing World of Warcraft would work on that instead?

Once you already have the world's theoretical physicists working on theoretical physics problems like like, what makes you think people in other fields would make a useful contribution?

Astronomers look for objects in the sky because they're astronomers. They aren't going to crack problems of theoretical high-energy physics, and they're not in the mood to play WoW 24/7...

Re:Can someone explain something to me?

[osu-neko]

...too much intellectual bandwidth, funding, and future research proposals go into the search for exoplanets.

Sorry for the double-post, but in my haste I neglected to notice the second and more pernicious fallacy here. There's a school of thought that says if you have problems A, B, C, and D to solve, but you determine problem A is by far the most important, that you should devote all your resources into solving A and ignore B, C, and D until you've solved A. This is an incredibly bad idea for numerous reasons, but principally there's the problem of diminishing returns. The more funding you throw at A, the less you're getting per dollar. Indeed in fields like science, it's by no means certain that you're getting anything at all -- the needed breakthrough may come on the same timetable regardless of how much money you throw at it. In the meanwhile, you make no progress on B, C, and D where even a few dollars would make immense progress. If A is more important, you throw more money at it, but you don't starve all the other problems, you throw money at them too, just less. Looking for objects in the sky isn't a very expensive task relatively speaking. And just in general, the optimal approach for maximizing progress on problems (whether it's research or other kinds of problems) usually involves an "all at once" approach, giving more to the priorities but not starving the others, and particularly in cases where it's not clear spending even more money on A would be at all helpful, whereas spending money on B clearly would be. Scientific problems in particular don't necessarily advance based on amount of money thrown at them.

A third problem here is that what you're asking for is solutions to known unknowns. We tend to prioritize finding answers to questions we already know, but really the most impressive scientific advances come when we discover things we didn't even know enough to know were in question. Thus, much of science should always be devoted to looking for new things, discovering stuff, etc. Sure, all we've found today was a rather uninteresting brown dwarf, but how much would our understanding of the universe have been advanced if we'd found something that we never even had an inkling might be there? At that point, throwing money at solving known issues with theoretical physics would seem truly wasteful compared to what we got just looking at to see what's out there. We look for exoplanets and brown dwarfs and things because as much as we think we know about them, until we look, we don't really know, and we could very well be wrong, and the consequences of what we discover in the process might be far more significant than any research project you can name, indeed depending on what we find, might be more significant than anything we can even currently conceive of.

Re:Can someone explain something to me?

[Daetrin]

Because they're astronomers and not astro-physicists or physicists.

If you mean why are they observing nearby stars instead of whatever observations you think would help astro-physicists and physicists with the kind of research you think is important, that would be because not everyone has your priorities.

1: It's quite possible that knowing what's immediately around us will prove of more practical value than high level physics. High level physics _might_ enable fantastic new technologies. Or it might not. Or it might, but at a much later date. We might end up launching unmanned probes and generation ships to nearby systems long before we get anything of practical benefit from high level physics.

2: If you want to base it on pure knowledge instead of practical results, why can't some people be more curious about what's around us than about esoteric forms of matter? Maybe finding out more about local systems (the ones we can observe most easily) will give us better ideas about where to look for alien intelligence, and wouldn't finding another intelligent race be just as amazing as figuring out what/where the dark matter is?

3: Return on investment. There is plenty of investment into high level physics. How do you think the Higgs Boson was (probably) found? But we've already picked a lot of the low hanging fruit in that area. Clearly the explosion in exoplanet data in recent years means technology has advanced to the point where such discoveries are fairly easy. No one knows for sure what we need to do to find the dark matter, but we know what we need to do to find more/more about exoplanets, so it's almost a guaranteed return on investment.

new dark matter results any day now

[peter303]

That very expensive special detector on the Space Station is reputed to announce interesting results any day now. Detecting certain classes of dark matter was one of its capabilities.

Congress had to fund a special extra shuttle launch to get this into orbit. Furtmore, the physicists decided to swap in a new set of magnets last minute, postponing it over a year.

Andromeda "collision" is more scary

[peter303]

Andromeda is trillions of times more massive and will "collide" with the Milky Way in two billion years. But they will interpetrate each other like ghosts passing in the night. Odds are unlikely there wont be a single stellar collision among the trillion stars during the Big Merge. The night sky will become rather interesting with multiple stellar bands lighting the sky.

Re:Proxima Centauri

[PhotoJim]

True, but Proxima Centauri is a part of the Alpha Centauri star system, so that still makes this the third closest star system.

Third closest system?

[rossdee]

What makes this the third closest system to earth?

The closest solar system is our solar system (orbiting the sun whish is 1AU away
the second is the Centauri system (Proxima Centauri and Alpha Centauri a and Alpha Centauri B
the third closest system is Barnards Star which is less than 6 LY away, so it is closer than this newly discovered system

Re:Third closest system?

[Anonymous Coward]

Debug your code. The index starts at zero.

very interesting

[kilodelta]

And I still maintain if we had funded NASA like we funded them in the 1960's and early 1970's we'd be at Alpha Centauri or Barnard's Star by now. But instead we'd prefer to fund military misadventure. However look at the private interest in mining asteroids - that will be cool!

Re:very interesting

[cusco]

With the assumption that NASA funding was going to continue unabated the roadmap in (IIRC) 1970 showed the opening of the first permanently manned Lunar base in 1984, with a manned mission to Mars launching by the end of the '80s. Sigh.

Re:very interesting

[Kjella]

And I still maintain if we had funded NASA like we funded them in the 1960's and early 1970's we'd be at Alpha Centauri or Barnard's Star by now.

Earth-Moon: 356,700 km (closest)
Earth-Mars: 54,600,000 km (closest)
Earth-Alpha Centauri: 42,479,700,000,000 km (~fixed)

Fastest spacecraft to date (escape velocity): Voyager 1 (1977), 17.145 km/s

Now assume we could launch at that speed and travel a straight line:
Moon: 6 hours
Mars: 37 days
Alpha Centauri: 75000 years, give or take a couple millenniums

To be there now, we'd have to have launched a rocket ship travelling at 0.1c (that's 30000 km/s) in the early 70s. Even the "Momentum Limited" Orion which is the closest thing to a semi-plausible design we have - if you call a rocket 140 times the size of the Saturn V loaded with 300,000 one megaton nukes plausible - was planned to take 133 years. Maintain it all you like, but don't be surprised when other people maintain that you have no idea what you're talking about.