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

A model for the dust envelope of the protoplanetary nebula LSIV-12degrees111 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 x 10(16) cm from the central star, is 0.072 at 0.55 mum. The temperature of the dust grains at the inner boundary of the envelope is 124 K. The estimated distance to LSIV-12degrees111 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 x 10(-5) Mcircle dot/yr. (C) 2003 MAIK 'Nauka/Interperiodica".