* Rigel is a blue supergiant star with a radius of about 78 times that of the Sun.

* Sirius is a white main-sequence star with a radius about 1.7 times that of the Sun.

While Sirius is the brightest star in the night sky as seen from Earth, this is due to its proximity to our solar system, not its size. Rigel is much farther away but is significantly larger and more luminous.