The Evolving Shapes of o Ceti and R Leonis

The sizes and shapes of the stars o Ceti and R Leonis have been measured in the mid-infrared. The observations were made using the UC Berkeley Infrared Spatial Interferometer (ISI), and they reveal details about the size, shape and asymmetry of both stars over several epochs in 2006. The star o Ceti appears to be rather symmetric, while the shape of R Leonis appears more consistent with a uniform disk plus a point source that provides approximately 9% additional intensity somewhere in the southern half of the star.