DENEB (Alpha Cygnus) is the 17th brightest as it appears in our sky
and makes the western apex of the famed Summer Triangle, which also
incorporates Vega and Altair. Though Vega and Altair are really quite
luminous, they are first magnitude primarily because they are close to
us, averaging only 25 light years away. Deneb, on the other hand,
may be as far as 2500 light years away.
Based on that distance, its awesome luminosity of over 200,000 Suns
makes it about the intrinsically brightest star of its kind (that is, in
its temperature class) in the entire Galaxy. If placed at the distance of
Vega, Deneb would shine as right as a well-developed crescent
Moon. Deneb is a true supergiant, its diameter, calculated from
its temperature and luminosity, is 200 times that of the Sun. If it
were placed at the center of our Solar System, it would extend to the
orbit of the Earth.
Non-LTE effects prevent from using Kurucz models to fit the UV flux
distribution of Deneb. Red crosses in the IUE spectra indicate
bad-quality points.
Back to the Flux Distribution page