Astronomy Digital Picture – 16 seconds, ISO 400, 13.7mm f/3.2, on 28 Dec 2006 3:24Am, Lakshmisagara.
14 Jan 2007
Sirius is the sparkling star of night sky, is also reffered as “Dog Star”.
Sirius is the first binary star system to be discovered. Sirius A – larger and brighter than the other, is three times the mass of our sun and over ten times brighter. Whereas Sirius B is a “white dwarf” star, invisible to the naked eye and packing the equivalent mass of our sun into an incredibly dense globe only 4 times the diameter of our Earth !
Sirius B traces an elliptical orbit around Sirius A, and their common center of gravity, directly face onto the Earth like the dial of a clock. They take 50 years to complete their orbit. Sirius B spins on it’s axis at an incredible 23 times a minute!
Sirius star system is located at about 8.5 light years from us, and is the brightest star in the night sky, with a visual apparent magnitude around -1.5.
The Ancient Egyptians were somehow aware of this unique relationship between our system and Sirius and marked the heliacal rising of Sirius as the first day of their calendar year. around January 1 it reaches the meridian at midnight.
Tomorrow’s picture – Sun God.
Posted by naveenln 
Astronomy Digital Picture of the Day 