Herschel Probes Huge Dog Star

The Herschel Infra-red Space Telescope, launched in May, is already giving good pay-off with the most in-depth imaging and spectrographic analysis of the hypergiant sun Canis Majoris.

Canis Majoris is, so far, the biggest star in the universe, first observed about two centuries ago, and it could go supernova, any millennium now! There is a good posting about it here at the BBC News website.

Info from Wikipedia states that, "If the Earth were to be represented by a sphere one centimeter in diameter, the Sun would be represented as a sphere with a diameter of one hundred and nine centimeters, at a distance of one hundred and seventeen meters. At these scales, VY Canis Majoris would have a diameter of approximately 2.25 kilometers."

So that's BIG, but big does not necessarily mean bright and it is often smaller stars that burn brighter and faster. Canis Majoris is also one of the coolest giant stars we know of and as a result is comparatively dim.