What is the difference between a "star" and a "sun"? (Beginner)

Are all of the points of light in the night sky, other than the moon, planets, and artificial satellites, that we call stars also suns?

A star is called a "sun" if it is the center of a planetary system. A large number of planets have been found that orbit other stars, thus making these stars officially "suns." Chances are that a large percentage of the stars in the galaxy also have planets orbiting them, which would make them suns as well. The number of extrasolar planets that have been detected is increasing very rapidly, as we find new planetary systems. So a large number of the stars that you see are also suns. However, many objects in the night sky are not stars. You mentioned man-made satellites, planets and the moon. From earth, there are many other objects that we see as points of light, such as far-away galaxies, so not every point of light is a star!


This page updated on June 27, 2015

About the Author

Cathy Jordan

Cathy got her Bachelors degree from Cornell in May 2003 and her Masters of Education in May 2005. She did research studying the wind patterns on Jupiter while at Cornell. She is now an 8th grade Earth Sciences teacher in Natick, MA.

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