A Search for Exozodiacal Dust and Faint Companions near Sirius, Procyon, and Altair with the NICMOS Coronagraph

Abstract

We observed Sirius, Altair, and Procyon with the NICMOS coronagraph on the Hubble Space Telescope to look for scattered light from exozodiacal dust and faint companions within 10 AU from these stars. We did not achieve enough dynamic range to surpass the upper limits set by IRAS on the amount of exozodiacal dust in these systems, but we did set strong upper limits on the presence of nearby late-type and substellar companions. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.