Cygnus, the Swan, flies down the summer Milky Way in the north; its bright stars form the Northern Cross, with Deneb at the tail and Albireo at the beak.
At a glance
| stars in the figure | 10 |
|---|---|
| nearest star of the figure | Aljanah, 72.7 light-years (22.3 pc) |
| farthest star of the figure | Deneb, 2,620 light-years (802 pc) |
| depth | the farthest is 36 × farther than the nearest |
Read off the piece’s own catalogue, the same values it draws with.
About Cygnus
Cygnus is an ancient Greek constellation, a swan with outstretched wings, its long neck reaching along the Milky Way. Deneb, at the tail, is a white supergiant of enormous power, faint-looking only because it is so far away; with Vega and Altair it makes the Summer Triangle. Albireo, at the beak, is a double that a small telescope splits into gold and blue.
The swan lies across one of the richest stretches of the Milky Way, where dark lanes of dust, the Great Rift, split the glow in two. The Cygnus Loop, the wreck of a star that exploded long ago, sits at one wingtip. Also in Cygnus is the pair 61 Cygni A and B, the first star system whose distance was measured by parallax. It is best seen on northern summer and autumn evenings.
What you see in the piece
Fly out to the Swan and Deneb stays bright from far away, because it lies much deeper than the rest; Aljanah, on a wing, is a near neighbour by comparison, and the cross falls apart.
Questions
What is the Northern Cross?
The Northern Cross is an asterism made of the brightest stars of Cygnus: Deneb at the top, Albireo at the foot, and the swan’s wings as the crossbar.
How far away are the stars of Cygnus?
They range from Aljanah, 72.7 light-years (22.3 pc), to Deneb, 2,620 light-years (802 pc): the farthest is 36 × farther than the nearest.