Ever since I've been involved with astronomy and a member of one of the local astronomy clubs, I have been told that the name Betelgeuse means "Armpit of the Giant". According to this account http://www.examiner.com/article/betelgeuse-the-history-of-a-star-name it never meant that at all. It really means "Hand of the Giant". To quote the next to last paragraph: "Scholars decided that the true origin of the name must be bat al-jauza', the "Armpit of the Giant." Unfortunately for these hard-working scholars, such a name never appeared anywhere in Arabic astronomy. Even more unfortunately, the name is just wrong: the "Armpit of the Giant" should be ibt al-jauza', not the bat al-jauza' they wanted." Another misconception that I've heard over and over at star parties is that Albireo is a gravitationally bound binary system. In this Wikipedia article http://en.wikipedia.org/wiki/Albireo and Burnham's Celestial Handbook, that fact has never been proven.