A constellation is a group of stars of the vault heavenly which enough close relations looked the appearance imagination of a figure onto the sky. A constellation is thus a asterism astronomy, an asterism is a remarkable figure drawn by particularly brilliant stars. particular. In the sky the stars of a constellation are very remote some of the others but seem grouped together there figures.
During the season of the spring, a characteristic triangle formed by the stars Arcturus of the constellation of the Cattleman, Spica of Virgo and Regulus du Lion, will help the observer to find a way in the starry sky. This heavenly triangle is called by the astronomers the triangle of orientation of the spring.
NB: by agreement the names of the stars of a constellation are prefixed by a Greek letter followed by the first 3 letters of the constellation, the 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).
The constellation of the Boötes has a shape looking like that of a kite. It is especially known thanks to stars Arcturus α BOo (magnitude 0,03 to 36,71 AL) and Izar ε BOo (magnitude 2,37 to 209,75 AL).
Arcturus the most brilliant have a diameter equivalent to 23 solar diameters.
The constellation of the Lion becomes identified thanks to a group of stars forming a characteristic drawing of sickle. We can easily observe this constellation in our hemisphere in spring.
The most brilliant star of the Lion is Regulus (α Leo). it is situated in 68 light years of the Earth.
This constellation is crossed by the Sun from August 10th till September 16th.
In the order of the zodiac, the constellation is situated between weakly brilliant Cancer on the West and the Virgo in the East.
This constellation contains several brilliant stars, such Regulus (α Leonis), the heart of the Lion, and Denebola (β Leonis), its tail.
The Lion also indicates a sign of the zodiac corresponding to the sector of 30° of the ecliptic crossed by the Sun from July 24th till August 23rd.
It is in this direction that it serves to the global location of the movement, still used in astrology.
Stars | Magnitude apparent | Distance (al) |
Regulus (α Leo) | 1,36 | 78 |
Denebola (β Leo) | 2,14 | 36 |
Zosma (δ Leo) | 2,56 | 58 |
Algeiba (γ1 Leo) | 2,61 | 126 |
Ras Elased Australis (ε Leo) | 2,97 | 251 |
The Small Lion is a boreal constellation constituted by Hévélius to cover a zone devoid of name, we find there that stars of the fourth magnitude.
The Small Lion is placed over the head of the Lion. To find it, it is necessary to look between the constellation of the Great Bear and the Lion.
The constellation of the Virgo is easily observable of our north hemisphere and serves as mark for the identification of the other constellations.
The Virgo contains a large number of distant galaxies among which some are visible in a telescope even average. This constellation is crossed by the Sun from September 16th till October 30th. In the order of the zodiac, the constellation is situated between the Lion on the West and the Libra in the East.
It is an immense constellation (the second of the sky, after the Hydra) and extremely former.
The Virgo also indicates a sign of the zodiac corresponding to the sector of 30 ° of the ecliptic crossed by the Sun from August 24th till September 22nd.
Stars | Magnitude apparent | Distance (al) |
Spica (α Vir) | 0,98 | 262 |
Vindemiatrix (ε Vir) | 2,85 | 102 |
Heze (ζ Vir) | 3,38 | 73 |
Auva (δ Vir) | 3,39 | 202 |
Zavijah (β Vir) | 3,59 | 36 |