Deneb

Deneb, Alpha Cygni, is the brightest star in the Cygnus (Swan) constellation, despite being at least thirty times more distant than the others. It is the twentieth brightest star as seen from Earth in the Milky Way, with an absolute magnitude of -7.2, making it among the brightest stars known.

Deneb's exact distance from the Earth is a matter of some dispute; most equally distant stars are not visible to the naked eye, and may be identified only by catalog numbers, if they are known at all. Figures from 1600 to 3200 light-years appear on various online sources. It should be noted that determination of distances at this range is very difficult; parallax cannot be used.

Its luminosity is about 60,000 times that of our Sun; if Deneb were a point source of light at the Sun's distance from Earth, it would be far brighter than most industrial lasers. It generates more light in one day than the Sun has since the American Civil War.

The name comes from the Arabic Al Dhanab, the tail. The same name was given to a number of different stars, notably Deneb Kaitos, the brightest star of the Cetus constellation.

Mythology

In the Chinese love story of Qi Qiao Jie, Deneb marks the magpie bridge across the Milky Way which allows the separated lovers Niu Lang (Altair) and Zhi Nu (Vega) to be reunited on one special night of the year in late summer. In other versions of the story Deneb is a fairy who acts as chaperone when the lovers meet across the bridge of magpies.