Brown Dwarf (image) University of Arizona Caption This graphic shows the range of sizes of a brown dwarf compared to Jupiter and the Sun and the Earth (to scale). Brown dwarfs are more massive than planets but less massive than stars. But they have similar diameters to planets such as Jupiter. Credit Image by Jon Lomberg, provided by Gemini Observatory Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.