What does this number measure?
A blue supergiant in the constellation Orion. Rigel illustrates the enormous variety of stellar dimensions. Its diameter depends on models and observations; a star does not have a solid surface defined like that of a rocky planet.
Compare the stated dimensions
The comparison uses the number in each fact sheet: altitude, height, diameter, length or distance, depending on the reference. Two values in metres do not necessarily describe the same property.
Source and limitations
Catalogue order of magnitude; a source is provided, but this measurement has not been individually audited.
Rigel, a blue supergiant: interpreted disc and colour, estimated diameter.