Slashdot Mirror
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.
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.