Deneb is the white supergiant at the tail of Cygnus, one of the most luminous stars the eye can see, bright in our sky despite its great distance.
At a glance
| type | white supergiant (class A) |
|---|---|
| distance from the Sun | 2,620 light-years (802 pc) |
| its light left it | 2,620 years ago |
| luminosity | 196,000 × the Sun |
| radius | 203 × the Sun |
| surface temperature | 8,530 K |
| constellation | Cygnus (Swan) |
Read off the piece’s own catalogue, the same values it draws with.
About Deneb
Deneb is a massive star that has left the main sequence and swollen into a supergiant, shining with tremendous power. Most of the bright stars in the sky are bright because they are near; Deneb is bright because it is intrinsically brilliant, and it lies much farther away than the other stars of the Summer Triangle, Vega and Altair.
It marks the tail of the swan and the head of the Northern Cross. Its brightness and spectrum vary slightly and irregularly as its surface pulsates, and it gives its name to a class of such luminous variables, the Alpha Cygni variables.
What you see in the piece
With HUMAN EYE on it looks similar to Vega and Altair in brightness. Fly out and it stays visible long after nearby stars of similar brightness have faded, a sign of how much more light it puts out.
Measured or modelled
Its distance is hard to measure because it is far and bright, and estimates disagree; its luminosity and size scale with whatever distance is adopted.
Questions
How far away is Deneb?
Deneb is about 2,620 light-years (802 pc) from the Sun, though its distance is uncertain.
How luminous is Deneb?
Its luminosity is 196,000 × the Sun, one of the most powerful stars visible to the naked eye.