h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

In my Entry on Berkeley http://www.h2g2.com/approved_entry/A3472986 I mentioned Alpha Centauri as 'the nearest star we see at night'. Now I find it's a trio. Question: if the three are circling each other (as Gnomon http://www.h2g2.com/approved_entry/A132797/conversation/view/F17533/T1930741 suggests, rather than a pair and extra) then how is Proxima Centauri nearer to us than the others? Your truly, Puzzled, Earth.

I'm not an expert, but I'd say that it's because the nearest Proxima comes to our Sun is 4.2 light years, and the other pair are 4.4 light years.

But you would be correct to call the closest system "Alpha Centauri", as it is the system nearest to us. <> I would say that is correct.

When we look at alpha Centauri at night, we only see one star, because the primary pair are so close and Proxima, a dim red dwarf, cannot be seen by the naked eye.

I hope that helps

GB

Ah. So it's only nearest to us sometimes.

Thanks for the advice; I won't bother changing anything then!

You are most welcome

Would you like to see it?

http://apod.nasa.gov/apod/ap051204.html