Procyon

Canis Minor with Procyon at the Bottom

Procyon (at the bottom of the poor photo or at the top of the Sirius photo) is the nearest neighbor to the Sirius system, and it is also a binary star with a white dwarf.  Procyon's white dwarf is somewhat less massive at 0.6 solar masses and quite a bit older too.    Procyon A itself is somewhat more massive than our sun and has evolved a bit off of the main sequence.   Procyon means "Before the dog" because it rose before its neighbour Sirius (a.k.a. the dog star) about 2000-3000 years ago along the Mediterranean.   Nowadays Sirius actually rise first because the Earth's rotation axis has shifted a bit with respect to the stars.   Whence all of the dog talk, Sirius is the brightest star in the constellation Big Dog, and Procyon is the brightest star of the Little Dog.   Procyon is also the name of the genus of animals that contain the raccoon who I guess comes before the dog as well.  Procyon and Sirius were terribly important to the Egyptians as Sirius rises just before the Sun when the Nile is about to flood.  Because at the time Procyon led Sirius the rises of Procyon just before the Sun gave the Egyptians some advanced warning.

The MOST satellite watched Procyon for a month in 2004 and contrary to expectations did not find oscillations it in flux.   Many stars including Procyon are thought to have convection regions within (thinking the roiling of the boiling pot of water).  The roiling motion causes the brightness of the star to vary slightly.  Astronomers thought that the variation would be strong enough to be see with MOST but it wasn't.  This was somewhat surprising and is still not well understood.