We conducted a survey for infrared excess emission from 16 nearby main sequence shell stars using the Multiband Imaging Photometer for Spitzer ( MIPS ) on the Spitzer Space Telescope .
Shell stars are early-type stars with narrow absorption lines in their spectra that appear to arise from circumstellar ( CS ) gas .
Four of the 16 stars in our survey showed excess emission at 24 \mum and 70 \mum characteristic of cool CS dust and are likely to be edge-on debris disks .
Including previously known disks , it appears that the fraction of protoplanetary and debris disks among the main sequence shell stars is at least 48 \% \pm 14 \% .
While dust in debris disks has been extensively studied , relatively little is known about their gas content .
In the case of \beta Pictoris , extensive observations of gaseous species have provided insights into the dynamics of the CS material and surprises about the composition of the CS gas coming from young planetesimals ( e.g . 25 ) .
To understand the co-evolution of gas and dust through the terrestrial planet formation phase , we need to study the gas in additional debris disks .
The new debris disk candidates from this Spitzer survey double the number of systems in which the gas can be observed right now with sensitive line of sight absorption spectroscopy .