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Although the constellation Cygnus is known as the swan or according to the Arabs, the Flying Eagle, it actually looks like a large cross formed by bright stars while its wings are completed by some dimmer stars. Cygnus is also known as the Northern Cross to distinguish it from the small and much brighter Southern Cross, which can be seen from south of the equator.
There are two conflicting Greek myths concerning Cygnus. The first is that of Orpheus, the great musician who was placed in the sky not far from his beloved lyre after his death. The second myth is that Cygnus the Swan is Zeus, king of all the gods. One day Zeus changed himself into a swan in order to visit the King of Sparta's wife in secret. It is not quite clear whether Zeus was afraid of the woman’s husband or his own wife, Hera.
The constellation Cygnus contains one of the loveliest double stars in the sky - beta Cygni or Albireo. You will need binoculars and steady hands to differentiate between the two members of this double. The bright star is a golden yellow while its dim partner is a sapphire blue. Their apparent magnitudes are 3.2 and 5.4.
The brightest star of Cygnus is alpha Cygni, whose name Deneb comes from the Arabic word for tail. It is found at the opposite end of Cygnus from Albireo. A star can be bright because it is relatively close to Earth or because it itself is intrinsically bright. Deneb is a prime example of the latter case. Deneb is 1,600 light-years from the Earth; the light from Deneb travelling at 186,000 miles per second, takes 1,600 years to reach us. A light-year is a measure of distance, not time. A single light-year is equivalent to 5,880,000,000,000 miles. Deneb is one of the most inherently bright stars in the sky. It is very roughly 60,000 times as bright, if viewed from the same distance, as our Sun.
Deneb is one of the three points of the Summer Triangle. This is an asterism best seen during the summer and autumn months. The Triangle's other two stars are Altair of the constellation Aquila and Vega of Lyra.