The Dust Ring of LBV Candidate HD 168625
Abstract
We present infrared observations and model calculations of the dust shell surrounding HD 168625 (IRAS 18184-1623). This object is a candidate Luminous Blue Variable due to its photometric variations and the presence of a detached dust shell indicating a major mass-loss episode several hundred years ago. We have conducted a multi-wavelength infrared study of HD 168625, and present here high-resolution near-infrared imaging from NICMOS on HST, which shows substructure in a shell that is clearly detached from the star. We also present temperature and optical depth maps derived from mid-infrared images, which illustrate the toroidal geometry of the dust shell. In addition the these observations, we have modelled the dust shell of HD 168625 using the radiative transfer code 2-Dust, using observationally determined stellar parameters and geometric dust shell parameters as a starting point. We present here a comparison of the model spectral energy distribution to infrared photometry data, and compare model and data images of the dust shell. The shell can be modelled by a dust distribution that is largely disk-like (equator-to-pole density ratio ~ 30) but with an elliptical midshell, as would be formed from the interaction of a fast wind with a pre-existing density constrast.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AAS...201.4908O