AAS Meeting #193 - Austin, Texas, January 1999
Session 89. Protoplanetary Disks, Molecular Clouds
Oral, Friday, January 8, 1999, 2:00-3:30pm, Room 6 (A and B)

## [89.03] Keck II Mid-IR Imaging of WL16, A Deeply Embedded Herbig Ae Star with an Extensive PAH Disk

M. Barsony (HMC), M.E. Ressler (JPL)

We present diffraction-limited, mid-infrared images of the ~ 800 AU diameter disk surrounding the Herbig Ae star, WL16. We find the disk radiates strongly in the aromatic hydrocarbon features at 7.7 \mum, 8.6 \mum, 11.25 \mum, and 12.7 \mum. By modeling the spectral energy distribution of the central, unresolved (\le 0.25\prime\prime = 40 AU) disk component, we derive a line-of-sight visual extinction of AV ~ 25 through the cloud to the source. The 60\circ inclination angle of the large-scale disk matches the inclination of the inner, hot (T = 2000K) gas accretion disk, observed in near-infrared CO emission lines. Millimeter continuum measurements place an upper limit of \le 0.001 M\odot on the disk mass, making this an optically thin disk in the mid-infrared. We conclude that WL16 is a normal'' Ae star which lies within the \rho Oph cloud behind a thick screen of foreground material. The prevalence of hydrocarbon disks surrounding Herbig Ae stars is just beginning to be explored.