Deneb

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Related to Alpha Cygni: Beta Cygni

Deneb

(dĕn`ĕb), brightest star in the constellation CygnusCygnus
[Lat.,=the swan], northern constellation located SE of Draco and NW of Pegasus. It was depicted as a bird by most ancient cultures. It is sometimes called the Northern Cross because five of its brightest stars form a huge Latin cross.
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; Bayer designation Alpha Cygni; 1992 position R.A. 20h41.2m, Dec. +45°15'. It is a white supergiant of spectral classspectral class,
in astronomy, a classification of the stars by their spectrum and luminosity. In 1885, E. C. Pickering began the first extensive attempt to classify the stars spectroscopically.
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 A2 Ia; its intrinsic brightness (about 60,000 times as luminous as the sun) is the greatest of all the bright stars. Thus, even though it is also one of the most distant bright stars, being about 1,600 light-years from the earth, it has an apparent magnitudemagnitude,
in astronomy, measure of the brightness of a star or other celestial object. The stars cataloged by Ptolemy (2d cent. A.D.), all visible with the unaided eye, were ranked on a brightness scale such that the brightest stars were of 1st magnitude and the dimmest stars
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 of 1.25, making it one of the 20 brightest. Its name is from the Arabic meaning "hen's tail," referring to its position in the constellation.

Deneb

(den -eb) (α Cyg) A very luminous remote white supergiant that is the brightest star in the constellation Cygnus and lies at one end of the long arm of the Northern Cross, with Albireo (β Cyg) at the other (the name Deneb is Arabic for ‘tail’). Deneb is one of the biggest and brightest stars known, with a mass at least 25 times that of the Sun. It has a luminosity of between 60 000 and 250 000 times the Sun's brightness, depending on the accuracy of our distance estimates for it. It has very low proper motion (0″.003 per year), and measurements of its very small parallax by Hipparcos suggest that it lies about 990 parsecs from the Sun, although other estimates place it 500 pc away. mv : 1.25; Mv : –7.2 or –8.6; spectral type: A2 Ia.

Deneb

[′den‚eb]
(astronomy)
A white star of spectral classification A2-Ia in the constellation Cygnus; the star α Cygni.