Sirius BInary and 2012 and why we wouldn't see it coming...

A full cycle of precession is roughly 25,627 earth years.

If sirius is the sun's binary companion and an mass orbits the sun and sirius on a cycle that makes seven complete orbits between the sun and sirius then a cycle would take 3661 earth years. (One seventh of 25627 is 3661 earth years).

To simplify the orbit between of an object over 3661 years... the object would spend 915 years traveling to sirius, 915 years on the far side of sirius, 915 years traveling back to the sun and 915 years on the far side of the sun (away from sirius).

Sirius is 8.6 light years from the sun. This is 9,460,000 million kilometers.

So if an object travels from sirius to the sun, or 9,460,000 million km, over 915 years, it would have to travel at an average speed of 10,335 million km per year. That would be an average of 28 million km per day.

Using the speed averages the *maximum* time of travel from the following planet distances:

- Saturn 1426.7 million km
- Days from Saturn to Earth: 50 days (calculated using 28 million km per day)

- Jupiter 778 million km
- Days from Jupiter to Earth: 27 days

- Mars 78.5 million km
- Days (Mars-Earth) 2.7 days

Of course, the speeds are just averages based on distance and a travel time and the speeds would be much greater closer to the sun (or sirius) and much slower farther out. The result of this would be that the estimated distance would close much faster meaning the object could arrive much more rapidly than the calculated numbers above indicate.

I know this is an oversimplification of the math, but there ya go...

So, we might not see something that orbits sirius and the sun coming until it's here and gone.