The least massive
and smallest main sequence stars are only about one tenth as large as the Sun. Figure 19-7 shows the relative sizes of the Sun and the largest and smallest main sequence stars.
Figure 19-7
The relative sizes of main sequence stars with spectral types of O3, G2 (the Sun), and M8
The O3 star is 15 times as large as the Sun, whereas the M8 star is one tenth as large as the Sun.