One of the coincidences of winter evenings is that the two brightest stars in the sky are close together.
Look toward the south at 8:30 p.m. tonight and you will see mighty Canis Major the Greater Dog, or Sirius, the brightest star in the sky, 40 degrees above the southern horizon.
Canopus, the second-brightest star in the sky, is directly south and only 5 degrees above the horizon. Even though it is low, Canopus is bright enough to be easily visible above the skyglow of Tucson if you look toward the south from the foothills.
It is easy to enjoy Sirius, as it is so bright and reasonably high above the horizon.
Sirius is about 26 times brighter than the sun and is “only” 8.6 light years from the sun.
Canopus is more difficult to enjoy, as it is not quite as bright as Sirius, and it is fairly low on the horizon for viewing from Tucson. In fact, Canopus is not at all visible from Canada and most of the continental United States.
Canopus is truly a far more magnificent star than Sirius. It is a supergiant 15,000 times brighter than the sun with a diameter 65 times that of the sun. Even though it is 313 light years away, Canopus’ intense nuclear fires produce enough light for it to be a dominant star in the night sky in the Southern Hemisphere.
