Stars and Their Sizes

Part of Scales of the Universe.

Stars and their sizes_HERO AMNH/D. Finnin

Our star, the Sun, is 1.4 million kilometers across. Dim low-mass stars are only a few tenths of that size. The largest stars are luminous red supergiants nearly a thousand times the size of the Sun. Most stars are about the size of the Sun when they are born, and become giant stars in their old age.

Scales of the Universe: 10(9) Meters
If the Hayden Sphere is the size of the blue supergiant star Rigel, then this model is the relative size of the Sun… Our Sun is a star of intermediate size, mass, and luminosity (light output). In its old age, the Sun will swell more than a hundredfold to become a red giant that is larger than the star Rigel.
The sun
AMNH/D. Finnin
A suspended spherical model from an exhibit of stars and their sizes
Sirius
AMNH/D. Finnin
Vega
AMNH/D. Finnin
Scales of the Universe: 10(8) Meters
Jupiter is the largest planet in the solar system. Its diameter is roughly one-tenth that of the Sun, and then times that of Earth.

In This Section

Exhibit The Sun If the Hayden Sphere is the size of the blue supergiant star Rigel, then this model is the relative size of the Sun. Exhibit Alpha Centauri If the Hayden Sphere is the size of the blue supergiant star Rigel, then this model is the relative size of Alpha Centauri. Exhibit Sirius If the Hayden Sphere is the size of the blue supergiant star Rigel, then this model is the relative size of Sirius. Exhibit Vega If the Hayden Sphere is the size of the blue supergiant star Rigel, then this model is the relative size of Vega.