Star clock
The winter sky in the northern hemisphere is filled with delicacies. This week, look for the brightest star in the night sky, and explore the star’s constellation of Canis Major, the larger dog.
The star in question is Sirius. It is only 8.6 light-years away and contains about twice the solar mass and shines more than 25 times brighter. The graph shows the view looking south from London at midnight on 29 December. Sirius will be unmistakable. Chances are high that it will flicker wildly as the bright light is refracted by the layers of our atmosphere.
Canis Major is the largest of Orion’s few hunting dogs. Canis Minor, the lesser dog, is higher in the air. It is characterized by the bright star Procyon, which contains 1.5 times the mass of the sun and is almost seven times brighter. From the southern hemisphere, Canis Major can be seen more easily. From Sydney, Australia, it will appear high in the northeastern sky.