POLARIS STAR

or

ALPHA URSAE MINORIS

 

The pole star is situated in the Small Bear constellation. It indicates the North. Indeed it is at less than 1 of the Earth axis of rotation. But Polaris hasn't always indicated the North and later (in a few years) it'll be another star that will have this role. Polaris is a double and variable star. Indeed, it goes together with another small star. Its visual magnitude varies from 1,80 to 2,13 on a period of 3 days 23 hours 16 minuts 13 seconds. It is situated 800 l.y. away from the Earth. It is easy to locate Polaris in the sky. This star is called with different names which are : Polaris, Alruccabah, Cynosura, Phoenice, Lodestar, Pole star, Star of Arcady, Tramontana, Angel stern, Navigatoria, Yilduz, Mismar but it can't confuse with the " shepherd star".

If you want to test yours knowledges, you can go to the exercise and if you want to know more , you can consult the bibliography.

sky chart of celestial north pole ( click on the chart to see great format )

group 38 - Anne GIRARD, Sonia GERMAIN, Cémilia DESCHAMPS.