Astronomers Discover Third-Closest Star System To Earth 151
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)."
These are the starts that are closest to me (Score:5, Funny)
Sheldon's going to have to fix his song.
Re:These are the starts that are closest to me (Score:5, Funny)
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.
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...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...
I always thought a brown dwarf was the actor who played the character Tatoo in Fantasy Island. Was Jean Claude Van Damme in Fantasy Island?
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That was my first thought.
If brown dwarfs can't sustain fusion (Score:5, Interesting)
then why are they considered stars?
Re:If brown dwarfs can't sustain fusion (Score:4, Interesting)
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.
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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.
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Because they can temporarily achieve fusion, which no planet can do.
It's like - you have guys, fat guys and really really fat guys (they're your planets, various sizes from terrestrial planets through the Neptunian planets to gas giants like Jupiter), and continuing in increasing mass, you have small blobs, medium sized blobs and gargantuan blobs (stars, from
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Question since you seem knowledgeable on the subject: Can/have all Brown Dwarfs achieved fusion? I did more reading since I posted my response, and it seemed like smaller Brown dwarfs had never achieved fusion while larger ones had, and this is one distinction that some astronomers think should lead to a reclassification. Of course, i read it on the internet, so not sure how much validity there is in what I read.
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AIUI, if it gets hydrogen fusion going, then it's a main sequence star, even if it's a tiddler. That's pretty clear, and because people want to kill other people, the minimal limits for hydrogen (proton) fusion have been researched thoroughly. Objects that don't get hydrogen (proton) fusion going are brown dwarfs, planets, or dust.
Observationally, if something has been hot
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Mod this late post up please, I am out...
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Did you spot the deliberate error? It's cobalt that's the give-away "you've been super nova'd" nucleide.
Re:If brown dwarfs can't sustain fusion (Score:5, Interesting)
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. ;-)
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then why are they considered stars?
IIRC, they can sustain fusion until all of the natural deuterium (which is not much) is used up, but then they stop because they're not big enough to fuse regular hydrogen. Its kind of like a wimpier version of a white dwarf star that stops burning because it can't fuse carbon.
Re:If brown dwarfs can't sustain fusion (Score:5, Informative)
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I say we kick Pluto out of the solar system since it's not a REAL planet. Let it spend the rest of it's life around a fake star!
Effing dwarfs.
Re:If brown dwarfs can't sustain fusion (Score:5, Funny)
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The term "little" could be construed as demeaning.
I think the currently preferred term is "differently sized" planets.
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I believe the proper term is "gravitationally challenged".
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Nope, Plutonium is okay. It's named after some cartoon dog.
Re:If brown dwarfs can't sustain fusion (Score:4, Interesting)
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.
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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.
I have that problem as well. Sometimes its gas, sometime its a brown dwarf. I need new underwear when I mistake the two.
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Because astronomy is still deeply wedded to a sort of archaic taxonomy that is based in the observations of Chaldeans and still has more than a few toes mired in its astrological foundations.
It's long past time that the entire discipline basically sits down and rewrites its nomenclature (giving as best possible use of the common terms for things such as stars, planets, nebulae, etc.). We've started by throwing Pluto back out into the outer darkness where it properly belongs, but it's only a beginning.
And where's the mass of the universe? (Score:5, Interesting)
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?
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(obvious typo: that's closest)
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I think that's the common definition of dark matter. It's just whatever apparent gravitational affects can't be accounted for by the 'visible (through a telescope) matter'.
new dark matter results any day now (Score:4, Interesting)
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.
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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 fi
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Re:And where's the mass of the universe? (Score:5, Informative)
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.
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If it interacts through gravity... how come it hasn't behaved like all other matter? Unless you're saying there's some force other than gravity which acts between stars....? I mean, what else influences visible matter that causes it to collapse into galactic disks -- and which doesn't affect dark matter?
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Good questions to ask, its something science does indeed want to figure out. But for right now dark matter exerts gravitational force in the models we are using to predict the universes structure.
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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).
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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.
But isn't gravity what ultimately gives galaxies their shape? Your statement makes it sound as if there are two types of gravity, the one that forms galaxies from non-dark matter, and the gravity between dark and non-dark matter.
Re:And where's the mass of the universe? (Score:5, Informative)
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.
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Yes, gravity is primarily what gives galaxies their shape.
Why isn't, then, the dark matter shaped like a disk, similar to a galaxy, rather than a sphere, as the OP states?
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Dark matter is merely interstellar lint, the remains of many, many missing socks.
Re:And where's the mass of the universe? (Score:5, Informative)
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.
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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? (Score:4, Informative)
http://arxiv.org/pdf/1110.2757 [arxiv.org]
Re:And where's the mass of the universe? (Score:4, Interesting)
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? (Score:4, Informative)
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 [wikipedia.org] to even a fraction of the amount needed.
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Actually, this was one of the first hypothesis for explaining the dark matter: the MACHO http://en.wikipedia.org/wiki/Massive_compact_halo_object
These MACHOs were studied statistically by methods like gravitational microlensing (e.g. OGLE).
These studies concluded that the brown dwarfs can explain 20% of the dark matter in the galaxy, no more.
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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.
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Protip: If you find yourself saying, "It seems so obvious that _____________," then an expert in the field probably already thought of it and examined it, and a google search would do you good.
As others have already posted, the idea of MACHOs has been explored, and is (as best as we can tell) not able to explain (most of) the missing matter.
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That leads to the other point. Dark matter is not just dark, as in hard to see. Its dark as in it only interacts via gravity. So light etc passes right through it and is not influenced by dark matter other than via gravity. The bullet cluster
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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?
Basically because the things they call dark matter are about six times the amount that there is for luminous matter*. While there is no doubt luminous matter we have not seen yet, it has been determined that there is not six times as much such unfound matter as there is stuff we already see. If such an amount of brown dwarves existed, then we would be able to detect them as they obscured other stars if in front of them, and detect them through gravitational lensing if they were behind them. Basically, the i
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Someone's bitter...
Brown dwarf system just 6.5 light years away... (Score:1)
...and it's headed RIGHT FOR US!!!
Andromeda "collision" is more scary (Score:4, Insightful)
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The gas will interact and that will have interesting effects including star formation. Galaxy collisions often result in the gas being stripped off the smaller galaxy. I think the Milky Way is to big to lose all its gas on the first pass.
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The current estimate is about 4 billion years. see wikipedia article on the subject. according to latest simulations, there is 50% chance the sun and its planets would be thrown three times the current distance from the galactic core, and a 12% chance the solar system would be ejected altogether. but this would have no effect on the planet's orbit around the Sun, the solar system would probably be undisturbed. long before then, expansion of the sun will cause the earth to be too hot for liquid water, i
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Hollyweird is out of ideas, all they can do any more is create crappy reiterations of someone else's original idea.
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Proxima Centauri (Score:1)
Article has error. Proxima Centauri is 4.24 light years away.
http://en.wikipedia.org/wiki/Proxima_centauri
Re:Proxima Centauri (Score:5, Funny)
Re:Proxima Centauri (Score:4, Informative)
True, but Proxima Centauri is a part of the Alpha Centauri star system, so that still makes this the third closest star system.
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Alpha Centauri itself is really two stars. We're stuck with names from the time before we could resolve individual stars in multiple star systems and it leads to misunderstanding.
Systems like ours, with just one star, are a minority in the Universe.
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Quite right. It's three stars in total: Proxima orbits the combined pair of Alpha Centauri A and B. If I recall, they orbit each other at roughly the distance of Neptune from the sun. If Earth were orbiting either, it would be a very interesting night sky for years at a time.
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A number of astronomers have pointed out that Proxima Centauri's exact distance and vector aren't known precisely. So, while it's generally thought that the star is likely in orbit around the Alpha Cen pair, the error bars on all the number include the possibility that it's just an interloper that will eventually go its own way.
It can be hard to get precise numbers for a dim object that's not very close to any other objects. It would be easier if there were some smaller objects close to Proxima Cen, bu
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True. The article also mentions that there is only about a one in one million chance that Proxima is not in orbit around Alpha Centauri A and B, based on what is known today. Astronomers treat it as being in orbit, and more data is being collected to refine the probability.
For it to have the same proper motion and not be gravitionally bound to A and B, it would have to have skirted by the Alpha Centauri system at just the right angle and speed to appear from here to be moving in the same direction and at
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Yeah, if required to place a bet, almost any astronomer would bet on Proxima Centauri being in orbit around Alpha Cen. But still, it's always good to put up pro forma objections pointing out that coincidences do happen, and the numbers really aren't in.
OTOH, this should be distinguished from the popular know-nothing approach, e.g. the climate-change deniers or the whole religious anti-evolution thing, that are based on willful ignorance of the data.
The Proxima Cen story is more like the ongoing scient
Unique names for nearby stars (Score:3)
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.
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How about we call them "Bruce" to avoid confusion?
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Only if a certain percentage of their solar system's mass or above is made up of ethanol.
At least on the weekends....
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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)...
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Cue the star name squatters.
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many of the visible ones already each have multiple names. make all the names you like, it doesn't matter.
Polaris, UMi, Ursae Minoris, Alpha Ursae Minoris, North Star, Northern Star, Pole Star, Lodestar, Guiding star
Barnard's star, Barnard's Runaway Star, Greyhound of the Skies, Proxima Ophiuchi, Velox Barnardi
Alpha Centauri, Rigel Kentm, Rigil Ken, Toliman, Bermbermgle
Betelguese, Alpha Orionis, Alpha Ori
Vega, Wega, Lucida Lyrae, Alpha Lyrae
Tau Ceti, Durre Menthor, Tertia Struthionum
Spica, Azimech,
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Most of the stars you list are quite far away. Only 9 of the 51 closest stars are visible to the naked eye.
These are the ones with names: Alpha Centauri, Barnard's Star, Sirius, Epsilon Eridani, Procyon, Epsilon Indi, Tau Ceti, Luyten's Star, Teegarden's star, Kapteyn's Star, Van Maanen's star. Some of the are still technical greek letter-constellation names.
More of the same (Score:2)
I seem to recall reading that the future of star formation in this Universe will involve increasing formation of brown dwarfs and a cacophony of rocky planets, as the supply of hydrogen for new stars dwindles and the "metals" from previous stars accumulates. Kinda sad, that all those rocky planets will be circling "stars" too dim and cold to make them suitable for life.
Can someone explain something to me? (Score:3)
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? (Score:4, Insightful)
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...
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In other words why are astronomers working on exoplanets when there are so many other (IMO) more interesting astronomical questions?
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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
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Data from seemingly unrelated surveys has been used many times in the past to prove important theries. So your question is like asking Hubbel "why do you spend so much time looking at starlight spectra?"
Oodles and oodles of methodical empirical data gathering happen all the time these days, but the only status reports the mass media is interested in carrying are those that feather the imagination of the general public. Like discovering things we might just possibly be able to send a probe to someday.
(And
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...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 les
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> I just don't understand the current astronomical obsession with nearby stars/solar systems and exoplanets.
Maybe you should read up on what astronomers are actually working on this decade, instead of what you *think* they are working on. Exoplanets are a relatively small part of the astronomical enterprise. This report is a good starting point:
http://www.nap.edu/catalog.php?record_id=12951 [nap.edu] (there is a free pdf download option if you register).
Discovered the third-closest? (Score:2)
Astronomers Discover Third-Closest Star System To Earth
What impresses me most is that they kept the third spot clear until they made the discovery. How dey do dat?
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If you don't understand that the "so far" part is always implied, you don't get what science is. There are very few absolutes. Theories are subject to revision, nothing wrong with that.
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What happens when the merge? (Score:2)
Will the combined mass be enough to start fusion and a main sequence star?
Will it have a period of instability resulting in high energy particle or "solar flare" emissions that could have implications to our solar system?
Third closest system? (Score:3)
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? (Score:4, Funny)
Debug your code. The index starts at zero.
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Which still leaves zero as the first.
very interesting (Score:4, Interesting)
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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
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Distance doesn't always follow visibility. There are things that are far away but are much brighter than some of the nearby stuff, so are easier to notice. For the example of our Solar neighborhood, by number and by mass most of the stars are faint (magnitude > 14), and "all" of the light comes from the most luminous ones (from here [astro.rug.nl]). What you see at 14 billion l.y. away is entire galaxies, not individual stars.