Cygnus

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This is the constellation, Cygnus, the Swan.  Cygnus is a summer and fall constellation lying astride the Milky Way Galaxy as can be obviously seen in this image.  The background star clouds are our view of the outer regions of the Milky Way's disc.  North of this point (upper right corner in this image) the Milky Way thins out substantially as we are looking out and away from the center of the galaxy.

The stars making up the endpoints of the traditional stick figure of the constellation have been slightly blurred to make them more visible in this image.  The five central stars make up the asterism, the Northern Cross.  The brightest star in the upper right quadrant is Deneb.  At magnitude 1.25, Deneb is one of the signpost stars we use to identify the constellation and marks one corner of the asterism, the Summer Triangle along with Vega in Lyra and Altair in Aquila.  The center star is Sadr at magnitude 2.23.  On the south end of the constellation (lower left) is the famous and beautiful double star Alberio.  Visually, this pair of stars presents a striking contrast of both color and brightness with one star being a bright blue star and the other being a dimmer orange-gold color.

Cygnus contains many famous nebulae as well including the North American and Pelican nebulae just northeast (up) from Deneb.  Just south of Cygnus' east wing lies the Veil Nebula Complex just visible in this image.  The Crescent Nebula lies just south of Sadr as does the open cluster M29.  Also around Sadr, primarily to the northeast is the Gamma Cygnus Nebula.  Gamma Cygnus is the Bayer designation for Sadr which is the source of radiation for this emission nebula.  The reddish color of these light years large clouds of gas is a result of hydrogen alpha light being emitted from this gas which is primarily hydrogen.

Date:  10/21/2006

Location:  Cheddar Ranch Observatory

Telescope:  Canon 28-135 telephoto @ f/3.5

Mount:  LXD55

Camera:  Canon 350D, Type 1 filter, ISO 400

Exposure Count:  41 x 3 minute, 123 minute total exposure

Guiding:  None