Deneb

Deneb is a blue-white supergiant of spectral type A2Ia, the brightest star in the constellation Cygnus (the Swan) at magnitude 1.25. Its distance is somewhat uncertain but is estimated at roughly 1,500-2,600 light-years, making it by far the most distant first-magnitude star. Deneb is extraordinarily luminous — roughly 200,000 times the luminosity of the Sun — and has about 19 times the Sun's mass and over 200 times its diameter. It is one of the most intrinsically luminous stars visible to the naked eye.

Deneb marks the tail of Cygnus the Swan and the top of the Northern Cross asterism. It forms the faintest vertex of the Summer Triangle along with Vega and Altair. Despite appearing fainter than its two Summer Triangle companions, Deneb is vastly more luminous — the difference is entirely due to its much greater distance. The rich Milky Way star fields surrounding Deneb are magnificent through binoculars, and the North America Nebula (NGC 7000) lies just 3 degrees to its east. Best observed from June through December.

The name Deneb comes from the Arabic 'Dhanab ad-Dajajah' meaning 'tail of the hen.' Multiple bright stars carry names derived from the same Arabic root (Deneb Kaitos, Denebola), as 'tail' was a common stellar designation. Deneb has been used for navigation across cultures and is a prominent feature in the mythology of many civilizations, often associated with birds or crosses.