Canis Major & Minor

Sirius is the brightest star in the sky and the 5th closest star system to the Sun at 8.6 light years. Sirius has twice the mass of the Sun and its White Dwarf companion is the closest White Dwarf star to our solar system. White Dwarfs are essentially Dead Stars that have exhausted their nuclear fuel and have gone through an end-stage gravitational collapse compressing their remaining mass into a volume roughly the size of Earth. They shine through the release of their latent heat, slowing cooling for billions of years to come. Before the companion devolved into a white dwarf 120 million years ago, it was the brightest star in the system with a mass 5 times that of our Sun.
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Viewing the diminutive White-Dwarf companion of the star Sirius (the brightest star in the sky) is very challenging and most amateur astronomers put this in their “Bucket-List” of astronomical objects to view. It has been said that a good indicator to tell if the seeing conditions are favorable for viewing is to take a look at the nearby binary star Rigel with a companion at a similar separation but one that is much easier to split due to the primary star being dimer. Here are comparison photos of both binary stars which I took – each is a single frame and identically cropped – the only difference between the photos are the ISO & exposure settings required to capture the companions. The right-hand photo shows the two photos merged which shows the similar separation of the secondary stars. In my opinion the visibility of Rigel B doesn’t necessarily speak to the visibility of Sirius B – perhaps the best that can be said is if you can’t see Rigel B due to either the seeing conditions or your equipment, you are not likely to see Sirius B on that particular night.
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Here is another photo of Sirius and the Pup taken through a Gaussian Mask which attenuates the brightness and scintillation of the primary star to enable the secondary to be more easily detected.
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Often called “The Winter Alberio” (see Cygnus double stars) due to its striking color contrast.
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Procyon shines at magnitude +0.4 making it the 8th brightest star in our sky. It is located at a distance of 11.4 Light Years which makes it the 14th closest star system to our Sun. Procyon is a F5 IV subgiant with a mass of ~1.5 Msun and like Sirius has a dim White Dwarf companion that orbits at a distance of 15 AU with a period of 40.8 years.
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