List of stars more luminous than any closer star  This is a list of stars which are more luminous than any closer star, that is, stars which emit more radiation than any other star within the same distance of the Sun. The luminosities are measured in bolometric luminosity and not by visual luminosity. For example, Alpha Centauri A is the most luminous star within 5 light-years of the Sun. In order to find a star more luminous than α Cen, the radius would have to be extended out to 9 light years, to include Sirius. The closest star more luminous than Sirius is Vega, at 25 light years, and so on.