Cygnus, the swan

Cygnus, the swan, flies down the Milky Way with its wings outstretched. Its brightest stars make a large cross, the Northern Cross, with Deneb at the top.

Where is it from where I am?

How to spot it: A large cross along the Milky Way, with Deneb at its head. Source (opens in a new tab)

Swan and cross

Ridpath (opens in a new tab) notes that the Northern Cross, as Cygnus is popularly called, is far larger and more distinctive than the Southern Cross. The NASA Night Sky Network (opens in a new tab) counts the cross as an asterism inside the constellation. The Greeks saw a swan's long neck, outstretched wings and short tail, flying along the Milky Way.

Deneb

Deneb marks the tail; its name is the Arabic dhanab, "tail" (opens in a new tab). It is a highly luminous supergiant about 1,400 light-years away, the most distant of all the first-magnitude stars, and one corner of the Summer Triangle.

Cygnus X-1

In 1964 a sounding rocket found eight X-ray sources; one, in Cygnus, became the first object identified as a black hole (opens in a new tab). Its companion is a blue supergiant, HDE 226868.

Where on Earth, and when

The whole key pattern rises from anywhere north of about 45°S.

South of about 62°S, none of it rises.

North of about 62°N, the whole key pattern never sets.

Its middle climbs at least 20° high, the finder's threshold for a suggestion, from anywhere north of about 31°S.

It is highest in the evening sky, at about 9 p.m. local time, in mid-September, from either hemisphere, wherever it rises. With daylight saving time, that is nearer 10 p.m. on the clock.

Worked out by this site from the Bright Star Catalogue, for a flat, clear horizon. Hills, buildings, haze and city light all cut into this; the air also lifts objects near the horizon by about half a degree. For your own place and night, use the sky finder.