The constellation of Capricornus, the Sea Goat looks like a misshapen triangle. It’s not the easiest pattern to make out, but thanks to some planetary crowding it’s a little easier to locate at present; both Jupiter and Saturn currently reside there. Two distinguishing features of the main pattern are a pair of middle-bright stars marking the east and west ends of this down-pointing triangle. The pair at the western end, nearest Saturn, are Algedi (Alpha (a) Capricorni) and Dabih (Beta (‘) Capricorni).
To the naked eye, Algedi looks double, but this is nothing more than a line-of-sight effect. In contrast, Dabih is a true binary, its companion a little closer than the 6.6 arcminute separation of Algedi, atjust 3.4 arcminutes. In reality, the Dabih system is far more complex than…