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Calendar of astronomy, September sky

Constellation Corona borealis

 Automatic translation  Automatic translation Category: children
Updated January 21, 2013

Between Hercules and Bootes is the constellation Corona Borealis. This small constellation in the northern hemisphere has a well-defined shape. Indeed, seven stars come together to form a kind of diademe Diademe: incomplete crown worn on the front of the head, a sign of great power.. Pearl Crown called Alphecca (​​α CrB) is the brightest star in this group. The study of the light spectrum shows another star accompanies Alphecca and revolves around it in a period of 14 days. Corona Borealis is actually made ​​of stars arranged in an arc of a circle, as the Corona Australis in the sky southern hemisphere. Corona borealis is quite easily, it is between Vega (α Lyr) and Arcturus (α Boo), an extension of the tail of the Great Bear, in a portion of the sky poor star. Corona Borealis refers to the crown of Ariadne, launched in heaven by Bacchus after have delivered in the island of Naxos, where she was abandoned by Theseus. In the constellation Corona Borealis, but further into the cosmos, at a distance of more than a billion light-years away, there is a cluster of more than 400 galaxies (M17).


nota: A constellation is a group of stars that sufficiently close to the celestial vault are gave the appearance of an imaginary figure drawn in the sky.

nota: By convention, the names of the stars in a constellation are prefixed by a Greek letter followed by the first 3 letters of the constellation, for example:
α  Ori, β Ori,... (Greek letters: α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ ς σ τ υ φ χ ψ ω).

nota: a light year is exactly 9 460 895 288 762 850 meters.

nota: M is the mark of the Messier catalog, a catalog of astronomical objects look like diffuse nebulae or galaxies.

Image: Constellation Corona borealis. Image reworked from the Open Source software Stellarium.

 Constellation Corona borealis

Clusters of galaxies in the Corona Borealis


Each galaxy belongs to a group of galaxies known as a cluster of galaxies. Each galaxy cluster belongs to a set of clusters is called a supercluster.
The cluster A2065 in the Corona Borealis is the richest clusters of galaxies that make up the Corona Borealis supercluster. Abell 2065 is a highly concentrated clusters of galaxies containing more than 400 objects, the brightest are magnitude 16.
The cluster of galaxies is more than one billion light-years from Earth. The cluster A2065 was used to Milton Humason and Edwin Hubble in 1929 to develop the Hubble law, at the origin of the concept of expansion of the universe.
The Corona Borealis supercluster concentrates many other galactic clusters. In 1961, George Abell's catalog in the registrant giving the number 13. Deep sky behind the Corona Borealis supercluster, also accommodates the supercluster (A2034, A2049, A2062, A2069 and A2083).


nota: M is the mark of the Messier catalog, a catalog of astronomical objects look like diffuse nebulae or galaxies.

nota: NGC (New General Catalogue) is one of the most popular catalogs in the field of astronomy with the Messier catalog.

nota: IC (Index Catalogue of galaxies, nebulae and groups of Stars), serves as a supplement to the New General Catalogue.

nota: A (Abell catalog of clusters of galaxies). It is a catalog published in 1958 by George Abell (1927 - 1983) which lists 4073 clusters of galaxies. 

Image: A2065 galaxy cluster discovered by Edwin Hubble in the Corona Borealis.

 A2065 galaxy cluster
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