Newly discovered extrasolar planet is the smallest known and has smallest host star

Artist's conception of the newly discovered planet MOA-2007-BLG-192Lb orbiting a brown dwarf "star" with a mass of only 6 percent of that of the Sun. Theory suggests that the 3-Earth-mass planet is made primarily of rock and ice. Observational and theoretical studies of brown dwarfs reveal that they have a magenta color due to absorption by elements such as sodium and potassium in their atmospheres. If the host star has a mass of 9 percent of that of the Sun, at the other end of the margin of error for the new microlensing data, the star would be a red dwarf about 100 times brighter than the brown dwarf, but 1000 times fainter than the Sun. Credit: NASA's Exoplanet Exploration Program