Passage II

How big a star looks at a given distance defines the star's angular size, (see Figure 1).

Table 1 gives of the Sun if it were observed from various distances. Table 2 gives of stars 8 light years away from Earth that have various diameters.

For a star to be seen as a disk through a telescope, the telescope's resolution, R, must be less than or equal to of the star. Table 3 shows R using yellow light for telescopes of various diameters. Table 4 gives R for a 10 m (diameter) telescope using light of different colors.