[SunkenCiv]

join or quit list APoD 'blog post new APoD topic Astronomy Picture of the Day topic & keyword Astronomy Chat, Bloggers & keyword Science Chat, Bloggers & keyword NASA's APoD archive Calendar 1995-present APoD on your desktop

[bigheadfred]

Interesting there are shadows.

Sigma Orionis is an interesting multiple binary, some of whose components can be enjoyed with binoculars.
Sigma is a multiple binary with one very close companion and two wider ones.

What is the difference here between a "multiple binary" and a quaternary star system? Is there no difference except moslems can't count past two?

[TheOldLady]

Pretty horse, as ever. It’s nice that the APOD shows it off every once in a while. Thanks, Civ!