The sun as a point of comparison Variations in stellar size With regard to mass, size, and intrinsic brightness, the Sun is a typical star. Other stars often have their respective quantities measured in terms of those of the Sun.
Many stars vary in the amount of light they radiate.
Aldebaran A, Arcturus, and Capella A are examples of giant stars, whose dimensions are much larger than those of the Sun. The latter has a radius some 560 times that of the Sun, whereas the variable star Betelgeuse oscillates between 600 and 900 solar radii. Several of the stellar class of white-dwarf stars, which have low luminosities and high densities, also are listed in Table 1. Sirius B is a prime example, having a size of 0.01 solar radius, which is comparable to the size of the Earth . Among other notable stars of Table 1, Rigel A is a young supergiant in the constellation Orion and Canopus a bright beacon in the Southern Hemisphere often used for spacecraft navigation.