The winter sky in the northern hemisphere is filled with delights. This week search out the brightest star in the night sky, and from there explore that star’s parent constellation of Canis Major, the greater dog.
The star in question is Sirius. Situated just 8.6 light years away, it contains about twice the mass of the sun and shines more than 25 times more brightly. The chart shows the view looking south from London at midnight on 29 December. Sirius will be unmistakable. The chances are that it will be twinkling wildly as its bright light is refracted through the layers of our atmosphere.
Canis Major is the larger of Orion’s pair of hunting dogs. Canis Minor, the lesser dog, is higher in the sky. It is marked out 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 more easily seen. From Sydney, Australia this week, it will appear high in the north-eastern sky.