fr en es pt
astronomy
 
 
 
 
        rss astronoo

Calendar of astronomy, March sky

Constellation Gemini

 Automatic translationAutomatic translation Category: children
Updated January 21, 2013

The direction of the constellation Gemini is indicated by the stars Rigel and Betelgeuse in the constellation Orion. Indeed, if we draw an imaginary line between the two stars and they are pursuing this line to the north-east, we reach then easily Gemini. It is a very extensive constellation in form of rectangle. The two brightest stars of the constellation are Pollux, on the head of the left Gemini (β Gem of magnitude 1.18 to 33.72 AL) and Castor on the head of the right Gemini (α Gem of magnitude 1.60 to 51.55 AL). Castor is actually a triple star system while Pollux is a giant. Other stars of the constellation Gemini are Wasat on the belly of the left Gemini (δ Gem of magnitude 3.52 to 58.82 AL), Mekbuda on the left knee of the left Gemini (ζ Gem of magnitude 4.03 to 1169.03 AL), Alhena on the left foot of the left Gemini (γ Gem of magnitude 1.95 to 104.81 AL), Propus on the left heel of the right Gemini (π Gem of magnitude from 3.33 to 349, 21 AL) Tejat under the dress of the right Gemini (μ Gem of magnitude 2.89 to 231.81 AL), Mebsuta on the dress of the right Gemini (ε Gem of magnitude 3.08 to 903.49 AL). Also found in the constellation of Gemini, a beautiful open cluster M35 (Messier 35).

 

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.

 Constellation Gemini

Image: Constellation Gemini. Image reworked from the Open Source software Stellarium.

Star clusters M35 and NGC 2158

    

Open clusters of stars can be near or far, young or old, diffuse or compact. They are usually found near the plane of our galaxy, the Milky Way. They contain 100 to 10,000 stars, all formed at about the same time. The presence of bright blue stars is often characteristic of young open clusters. M35, on the upper left of the image is relatively close to 2,800 light-years away, relatively young, 150 million years and relatively diffuse, with about 2500 stars spread over a volume of 30 light years. NGC 2158 is a other star cluster at the bottom right of the image it is a grape of stars older and more compact, it is clearly shown on the image. NGC 2158 is four times more distant than M35, more than 10 times older and more compact with many more stars in the same volume of space.

 

The bright blue stars of NGC 2158 have self-destroyed, leaving the cluster in light of older stars and therefore more yellow. These two groups of stars are visible in the constellation Gemini.

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.

Image: Star clusters M35 and NGC 2158.
Credit & Copyright: Dieter Willasch (Astro-Cabinet)

 Star clusters M35 and NGC 2158
 
           
 
star
 
1997-2013 © Astronoo.com - Astronomy, Astrophysics, Evolution and Earth science.
Reproduction prohibited without permission of the author.