Epsilon Cygni (ε Cyg / ε Cygni) is a star in the constellation Cygnus. Its traditional name is Gienah, however Gamma Corvi has an identical traditional name. In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... A Julian epoch is an epoch that is based on Julian years of exactly 365. ... 2000 is a leap year starting on Saturday of the Gregorian calendar. ... Most stars are of nearly constant luminosity. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ... Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ... In astronomy declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... In astronomy, the solar radius is a unit of length used to express the size of stars and larger objects such as galaxies. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standardized distance away. ... In physics, luminosity is the density of luminous intensity in a given direction. ... The solar luminosity is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars. ... The historical temperature record shows the fluctuations of the temperature of the atmosphere and the oceans throughout history, and in particular since 1850. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... Orion is a remarkable constellation, visible from most places on the globe (but not always the whole year long). ... Cygnus (from the Latin word Cygnus, meaning swan) is a northern constellation. ... Gamma Corvi (γ Crv / γ Corvi) is a star in the constellation Corvus. ...

Epsilon Cygni is a cool orange giant star that is, as many visible stars tend to be, well along in terms of its stellar evolution. While young in comparison to the Sun its larger mass gives it a much shorter lifespan, and the star is in the beginning stages of its death. In astronomy, stellar evolution is the sequence of changes that a star undergoes during its lifetime, the millions or billions of years during which it emits light and heat. ... A sun is the star at the center of a solar system. ...

The name "Gienah" derives from the Arabic word for wing, جناح janāħ.

External link

• http://www.tcaep.co.uk/astro/constell/20460042.htm