COMETARY DUST IN THE DEBRIS DISKS OF HD 3l648 AND HD l63296: TWO 'BABY' beta PICTORIS STARS

摘要

The debris disks surrounding the pre-main-sequence stars HD 31648 and HD 163296 were observed spectroscopically between 3 and 14 mu m. Both stars possess a silicate emission feature at 10 mu m that resembles that of the star beta Pictoris and those observed in solar system comets. The structure of the band is consistent with a mixture of olivine and pyroxene material, plus an underlying continuum of unspecified origin. The similarity in both size and structure of the silicate band suggests that the material in these systems had a processing history similar to that in our own solar system prior to the time that the grains were incorporated into comets.