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Nemesis, the Sun's Binary Star Companion?
0xC2 writes "The Binary Companion or 'Nemesis' theory asserts that a yet-to-be discovered companion to our Sun may actually exist. Recent observations of two nearby stars (assumed companions) show debris disks 'strikingly like the Kuiper Belt int the outer part of our Solar System'. The Binary Research Institute site is devoted to the theory, and presents a concise introduction, list of evidence, and sample calculations in support of the theory. A fascinating read, although the physics and related calculations are not trivial." Has the 'unique theory on the internet' vibe to it, but interesting nonetheless.
Isn't that Microsoft? Oops... Wrong article...
On a scale of "faked moon landing" to "electric universe", I rate this 'theory' a solid "roswell alien autopsy"
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As the slashdot crowd is pretty much clueless about astronomy I expect lots of Funny rated comments to hide our ignorance on the subject, right guys?
You'd like to think so, wouldn't you? But as everyone knows, this is a matter for astrologers, which you clearly are not. Otherwise you'd know that making jokes about jokers joking to obscure their ignorance is itself merely a joke of an argument, so we cannot, even jokingly, take the argument in front of you.
Don't disappoint your bird dog. Go to the range.
Scientific Amercian ran a story several years ago about this. One of the pet theories at the time was that periodic extinctions (which haven't been proven periodic) were caused by objects like comets getting kicked out of the Oort every now and then which could in turn be explained by just such a neighbor star. Nasa has a (very short) page here: Imagine the Universe
... could we possibly find the outer planets by observing their influence on the inner planets' orbits, if there were a freaking brown dwarf in the neighborhood that we didn't know about?
Something like that would've ruined Kepler's whole day.
The summary states...
Recent observations of two nearby stars (assumed companions)
Whereas the space.com article states...
Each of the two disks has a sharp outer edge that might be caused by an unseen companion star
READ THAT AGAIN FOLKS - they are NOT assuming these two stars are companions. They are NOT a binary star system. They are simply two stars that have similar disks as our own solar system. They think a POSSIBLE cause for these disks MIGHT be an unseen companion, but NO unseen companion has been seen. This discovery leads NO MORE CREDIBILITY to the nemesis "theoory" whatsover - all it says is that there are other stars with similar structures to our own. The cause of this structure has not been observed.
Isaac Asimov has a novel with this exact premise, written in 1989, titled Nemesis (as if you expected something different). "Evil" companion star for the sun which caused all the mass extinctions, etc. Of course, in the novel there are multiple civilizations, a battle over whether Earth should be saved, etc... but the basic premise is the same. 17 years later, still just as fictional as it was then.
Actually I am a physicst, and while I'm not an astronomer, I do work with "dynamics" on a fulltime basis.
Not to mention, all but one real astronomer also think this theory is ridiculous. The site linked is by an AMATEUR astronomer, not someone with a formal training in the hard sciences. I'm not contradicting a specialist, I'm contradicting a whackjob internet troll. No, not you - the guy with the binary solar system website.
You don't need a companion to produce a sharp edge in the Kuiper belt. Simulations have shown that. Anyone who makes the assertion that the edges suggest such a thing ought to have at least become familiar with that research.
Furthermore, the analogy to Saturn's rings is, I suspect, misleading. The moons that directly shape the outer edge of the A ring are close to the ring and small. (They are tied to other moons via resoances so the whole system is strung together, but that's not what's being argued for here.) A star would be much more massive than the Kuiper belt and would seriously disrupt the system rather than maintain it. (It would also be pretty obvious if it were just beyond the orbit of the outer edge of the Kuiper belt. We'd feel it here, for a start.) A more distant star might be able to hold back the edge of the belt with a resonance, but that's a different thing. And odds are that such a companion would destroy a belt more readily than maintain it. (Look at Jupiter and the asteroid belt.)
It should also be noted that 300 million years is a short time in solar system terms. It's even shorter for the outer solar system where it's about one million orbits. Since things move slowly and there is little material out there, spreading is very slow. Ones the material is placed there by a larger body (like Neptune), it tends to stay put for quite a while.
I don't think you truly appreciate how BIG our solar system is. If there's a twin to our star, it would seem so far away that it would seem like it had nothing to do with us. e.g. From Pluto, our Sun looks like nothing more than a particularly bright star. Now given how far away this star would be, its gravitational effects might be difficult to detect. In fact, IIRC, there are still quite a few odd effects that the discovery of Pluto didn't quite account for. (Not big enough.) So maybe we've finally found our Planet X. Except that it isn't a planet at all. :-)
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Yes I do realize binary star systems are not rare. Not detecting it by visible light is exactly WHY classical mechanics comes into play - all you're really doing is dealing with a bunch of forces that go like 1/r^2. Investigating it for the sake of completeness is certainly not folly - however the arguments on the website linked in the article are nonsense.
I can't find it again at the moment - but I saw somewhere that they implied that the inaccuracy of predictions in precession over time was a result of our current theories being flawed, and that the binary theory somehow magically removed this inaccuracy. This is an example of the utter bullshit that anyone with an understanding of nonlinear dynamics would notice immediately. You're dealing with a many-body system here. That's inherently chaotic. That means, it's exponentially sensitive to initial conditions. Therefore, as time goes on your results get worse and worse due to small measurement errors in your initial conditions. NO MODEL can remove this effect and still claim to use newtonian physics - the equations are nonlinear and involve more than three objects interacting - therefore the equations of motion are chaotic. Period.
OF COURSE YOU CAN GET MORE ACCURATE RESULTS WHEN YOU PUT IN AN IMAGINARY EXTRA OBJECT - you can TUNE the parameters of this object arbitrarily to try to fit the experimental data. If I collect a bunch of data from all kinds of experiments, I can easily find a tenth order polynomial and get a very accurate fit to the data. This is also completely meaningless because all those fit parameters have no physical meaning.
The linked article is not really about Nemesis, a distant companion to the Sun supposedly linked to regular massive exctinctions through its influence on the Oort cloud (where comets come from).
It is, however, about an unseen Sun companion responsible for the precession of the equinox. The precession of the equinox is the observation that as the Earth orbits the Sun, after a full year around the Sun the Earth does not realign itself with the distant stars, there is a difference of about 50 arcseconds. This correspond to a period of about 24,000 years.
Current theory for precession says the phenomenon is due to tidal effects due to the Moon acting on the non-perfectly-spherical Earth.
TFA makes the simple point that this could be also more easily explained if the Sun was revolving around an heretofore unseen companion for the same period. This would also explain a number of other more complex phenomena, such as why this the precession rate seems to slowly, but undoubtedly change with time, why the angular momentum of the Sun appears to be so low compared to that of the planets, etc.
TFA goes on to make prediction where this companion might be in the sky, and how far away it should be (between 0.01 and 0.03 of a LY), using nothing more complicated than basic Newtonian celestial mechanics.
Well, time will tell, and I'm not an astronomer, but the theory is actually very simple and testable (in the mid to long run), so either evidence will mount in this direction or it will be disproved.
For example we could measure precession rates on Mars. Since Mars has no large satellite, if it is found to have a precession rate similar to that of the Earth, then this will be very strong evidence that the tidal theory cannot be correct, and that the distant companion one is more likely to be. On the other hand if precession on Mars is very low, then this theory cannot be correct.
In short I think the guy might be wrong but he is no crackpot.
> I sense an evil twin joke coming on.....
I bet Nemesis looks exactly like the Sun, but with a stylish 200,000-mile-wide Evil Spock goatee.
Proxima Centauri, a red dwarf, is 0.12 solar masses, about 270,000 AU away, and was discovered in 1915.
It seems brown dwarfs cap at around 90 jovian masses (0.08 solar masses).
"The Nemesis theory says that it exists about 50,000-100,000 AU away, has an orbital period of 26 million years, and is a brown dwarf."
ballpark absolute magnitude of a brown dwarf: 17
absolute magnitude of the sun: 4.8
difference: 12.2
Apparent magnitude of the sun at 1 AU: -26.73
apparent magnitude of sample dwarf at 1 AU: -26.73 + 12.2= -14.53
Add 5 apparent magnitude for multiple of ten of distance
100,000 AU = 10^5 AU, 5 * 5 = 25, 25 + (-14.53) = 10.47
Apparent magnitude of sample dwarf at 100,000 AU = 10.47 (round to 11)
Coincidentally, the apparent magnitude of Proxima Centauri is also 11
Apparent magnitude of Neptune, discovered 1846 = 8 (about 16 times brighter)
Apparent magnitude of Pluto, photographed 1915 = 14 (about 16 times dimmer)
Apparent magnitude visible by ground-based telescopes = 27 (2.5E6 times dimmer)
Apparent magnitude visible by Hubble = 30 (4.0E7 times dimmer)
From the looks of things, Nemesis would have been showing up in astronomical photographs starting from the last decade or so of the Nineteenth Century. Curiously, the first confirmed sighting of a brown dwarf was in 1995 (first theorized in the 1960s). Now, unless the spectral pattern put out by this brown dwarf Nemesis somehow looks like much larger, hotter and brighter stars, it would have been Big News in Astronomy that such an odd star exists, regardless of its distance from us.
"It's like putting a telescope in your car while driving down the road and expecting to be able to find a parallax between observations"
Time between the two photographs over which the motion of Pluto first became apparent: 6 days
Orbital period of Pluto: 90,600 days
Sweep of arc made by Pluto for its discovery ~ 1 minute, 16 seconds of arc
Time between the two photographs over which the motion of Quaoar first became apparent: 180 minutes
Orbital period of Quaoar: 105,000 days
Sweep of arc made by Quaoar for its discovery ~ 1.5 seconds of arc
You say Nemesis may have an orbital period of 26 million years. Kepler says an object 100,000 AU away should have an orbital period of about 32 million years. We'll take the slower number:
Sweep of arc made by Nemesis in the past 50 years ~ 2 seconds of arc
And an interesting quote about the discovery of real nearby brown dwarfs in Epsilon Indi, 12 light-years away (source):
If 12 light-years "appears to move quite rapidly in the sky," why not 1.2 light-years?