Circumstellar Dust Disks around Stars with Known Planetary Companions

We have searched six stars with known radial velocity planetary companions for circumstellar disks. Disks are expected around stars with planetary systems that accreted from regular protoplanetary disks, and remnant disks are expected to be similar to our solar systemÏs Kuiper Belt. To date, we have detected circumstellar disks around three such stars : 55 Cnc, o CrB, and HD 210277. All these systems now resemble mature planetary systems with Jupiter-mass companions and Kuiper BeltÈlike disks. Our previous detection of the 55 Cnc disk (Trilling & Brown) is included here to place that disk in the context of the other two newly detected disks. Measuring the inclinations of the disks and assuming the disks are coplanar with the planetsÏ orbits determines the masses of the planets around these three stars to be and respectively (1 is one Jupiter mass). We also report 1.9 ~0.4 `1.1 M J , 1.5 ~0.1 `0.2 M J , 2.2 ~0.2 `0.6 M J , M J nondetections for three starsÈ51 Peg, t And, and Gl876Èthat are known to have radial velocity companions. A number of possibilities exist to explain nondetections of disks, from the absence of a disk to limits on disk mass, radial extent, or inclination. We may also be looking through a diskÏs central hole, especially for the nearby star Gl876. The radial brightness proÐles of each of the observed disks follow a power law with index D[5, including a power of [2 from the stellar Ñux drop o†, similar to the suggested value for our solar systemÏs Kuiper Belt. This likely suggests that uniform physical processes govern the Kuiper BeltÏs population out to at least 100 AU, and may be ubiquitous among disks. Last, we discuss how disk characterizations can lead us toward reÐning theories of planetary system formation. Subject headings : circumstellar matter È Kuiper Belt, Oort Cloud È planetary systems È solar system: formation