This occurs when the Sun and Moon are not exactly in line, and the Moon only partially obscures the Sun. When a total eclipse occurs, only a small line is traced out where viewed from Earth the Sun is completely obscured. However there are other areas surrounding this "line" where there is still shadow, but part of the Sun is still visible. Population I Stars These stars contain large amounts of elements that are heavier than helium. These heavy elements were produced by earlier generations of stars, and could have been spread by supernova explosions. Our own Sun is a Population I star. Population I Stars tend to be blue in colour and are younger stars. They are common in the spiral arms (the disk) of the Milky Way Galaxy.