There's a whole slew of objects that astronomers aren't sure whether to classify as "failed stars" or "overgrown planets." ...

Add Yahoo as a preferred source to see more of our stories on Google. White dwarf stars, like this one shown shrouded by a planetary nebula, are much smaller than stars like our Sun. NASA/R. Ciardullo ...

CAPE CANAVERAL, Fla. -- For the first time ever, astronomers have discovered seven Earth-size planets orbiting a nearby star - and these new worlds could hold life. This cluster of planets is less ...

Studying the orbits of thousands of exoplanets shows that large planets tend to have elliptical orbits, while smaller planets tend to have more circular orbits. This split coincides with several other ...

Astronomers studying extreme planetary systems have identified worlds so massive that they rival the smallest stars in size. These giant planets blur the line between planetary and stellar ...

Scientists identify exoplanet candidate HD 137010 b, a possible Earth-size world orbiting a Sun-like star 146 light-years away ...

A giant planet the size of Saturn orbiting a sun-like star has potentially been identified in our nearest neighbouring stellar system, Alpha Centauri. At just four light years from Earth, Alpha ...

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights. The sun will someday die. This will happen when it ...