It's common usage to call other stars at the center of planetary system "suns". For example: > As we came to understand that the stars in the sky are other sun

It's common usage to call other stars at the center of planetary system "suns". For example: > As we came to understand that the stars in the sky are other suns [...] - http://science.nasa.gov/astrophysics/focus-areas/exoplanet-exploration/ http://science.nasa.gov/astrophysics/focus-areas/exoplanet-e... See also the 2nd definition at http://www.merriam-webster.com/dictionary/sun http://www.merriam-webster.com/dictionary/sun : > : any star that has planets which move around it