Just been reading an interesting theory that canopus may ,rather than being a white giant star ,but a star in the process of shrinking down to a white dwarf having already gone through the red giant stage.sadly it's a star few of us north of about 35 degrees north ever get to see unless we head south.home of frank Herberts arrakis in dune also the star which pioneer 10 and 11,voyager 1 and 2 steered by,probably New horizons used it too?I would have thought that there would be evidence of novaing(if that's a word?) Around canopus if it was compacting in?not sure how long it takes for a red giant to collapse into a white dwarf?