"Rigel Kentaurus" is the old name for "Alpha Centauri". Alpha Centauri is about 4 light years away and most assuredly is a binary star. In fact, astronomers are not sure but it may be possible that it's actually a trinary system, because the red star Proxima Centauri may or may not actually be orbiting the two stars of Alpha Centauri.
The reason this actually doesn't surprise me comes from this entry of Atomic Fungus:
I had an opportunity to play around with "Distant Suns" Special Edition--the freeware demo version available for download from the company's web site. I can't recommend it, though. While I was fiddling with it, it crashed so hard that I couldn't shut down my computer! When I tried to shut it down, I'd get an error message claiming that RUNDLL32 had caused an error in GDI.EXE and the progam would terminate. Yahoo, that really makes me want to shell out money for the non-crippled version!I mean, if they can't get basic facts about the closest frickin' star to our own, what else do they have wrong? On top of the program crashing for no apparent reason?
Hence the sarcasm.