An article to be published in the “Astronomical Journal” describes a study of possible errors made in the density estimates of the exoplanets discovered using the transit method. Elise Furlan of Caltech/IPAC-NExScl and Steve Howell of NASA’s Ames Research Center analyzed the effect of the presence of a companion star on estimating the density of exoplanets in those systems, concluding that some of them are actually less dense than calculated.