Thursday, January 8, 2015

What's that bright star in the south?

This time year people notice a bright star rising in the south in the early evening. While low, the star's light is scattered, creating a sparkling effect that's noticeable because of it's brightness. That star is the brightest star in our night sky, Sirius. (Pronounce in English as "serious"). Sirius is also the heart of Canis Major, the great dog:

Sirius is a binary star system: two stars orbiting a common center of gravity. Sirius A is the brighter star, and Sirius B is the dim but observable companion. Sirius B can be seen in a telescope, but it requires good optics and good viewing conditions. However, the orbit of Sirius B is taking it to it's farthest point in relation to Sirius A, making it easier to see apart from the glare of Sirius B:

When Sirius is at its highest point in the sky, viewers in the lower part of the United States, Southern California for me, can also see the second brightest star in the night sky, Canopus. It appears in the bush of the picture above, but the following picture shows Canopus a little brighter after moving out of the bush:

Look just to the right of the bush, the lower right, and you'll see Canopus just above the horizon.


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