A model for the dust envelope of the protoplanetary nebula LSIV-12°111

Abstract

A model for the dust envelope of the protoplanetary nebula LSIV-12°111 is computed using measured fluxes of the object from the UV to the far-IR. It is assumed that the spherically symmetrical envelope is comprised of silicate particles with a standard MRN size distribution, whose number density varies inversely proportional to the square of the distance. The optical depth of the envelope, whose inner boundary is 5.6×1016 cm from the central star, is 0.072 at 0.55 µm. The temperature of the dust grains at the inner boundary of the envelope is 124 K. The estimated distance to LSIV-12°111 is 3.8 kpc. The current mass-loss rate of the object derived from a self-consistent solution for the radiative transport and motion of the dust in the envelope is 1.0×10−5M⊙/yr.