Chris Bailey, age 11, of Florence, S.C... for his question:

HOW BIG IS A STAR?

Our friendly sun is an average size star. If this ball of blazing gases were hollow, it could swallow a million earth size planets and still have room for two helpings of dessert. Though no two stars in the heavens are exactly alike, most of them are more or less the same size as our average sun ¬which has a diameter of about 860,000 miles.

However, among the total star population there are dwarfs, giants and supergiants. The white dwarfs are white hot, and most of them are about as big as large or small planets. If one of the giant stars were to replace our sun, it could spread beyond the earth's orbit. One of the supergiants would spread way beyond the orbit of Mars.

The largest supergiant we know has a diameter 3,000 times longerthan the sun's  and would spread way beyond Jupiter.