NOW you now why it’s called the Dog Star. Anyway, here are your complementary Canis Major facts:

Canis Major intersects the Milky Way.

Canis Major contains the neutron star RX J0720.4-3125 with a radius of 5km, and the red star hypergiant VY Canis Majoris with a radius of 990’000’000km.

Canis Major is the only dog constellation which actually looks like a dog.