I recently saw the documentary, The Great Year, and toward the end they bring up the idea that our sun is actually part of a binary star system. Our astronomy class never covered such a concept, and the idea boggles my mind. Could this be true?

Maybe if you're crosseyed.

BigMoosie is correct. The answer is no. Sol is not part of a binary system.

 

I suspect the idea may have arisen from certain theories that our solar system was influenced in its development by the gravity from another star passing close. However, even if this was true, it was never part of our system.

I recently saw the documentary, The Great Year, and toward the end they bring up the idea that our sun is actually part of a binary star system. Our astronomy class never covered such a concept, and the idea boggles my mind. Could this be true?

 

Isn't the alpha centauri, our nearest neighbour, a 2 or 3 star system. If we aren't part of that how could we be a binary with something else.?

the documentary stated that it could be with a brown star or a white dwarf, or possibly something we have overlooked. They also claim that each passing of the sun and it's partner happens every 24,000 years. It was interesting to think about. Here's the website...

http://www.thegreatyear.com/thegreatyear/index.shtml

and

http://www.thegreatyear.com/thegreatyear/tgy_facts.shtml

some people have also proposed Banards Star as our binary star.

and some more sites for those who are interested...

 

http://www.space.com/scienceastronomy/solarsystem/nemesis_010320-1.html

 

http://en.wikipedia.org/wiki/Nemesis_(star)

some people have also proposed Banards Star as our binary star.

 

I dont know who would propose something so stupid, but you shouldn't listen to anything else they say. I looked up how far away Berhnards star is (about 6 light years, further than alpha centauri). A quick calculation shows that Berhnards star would have an accelertation due to gravity from the sun of something on the order of 10^-12 m/s^2. Which is to say, the effect is effectively zero.