High-resolution, far-infrared observations of NGC 2071

The far-IR emission of the visible reflection nebula NGC 2071 has been resolved at both 50 and 100 microns along several directions. The observations reveal an extended, roughly spherical source with an average source diameter of about 12 arcsec or 4700 AU at 50 microns and about 16 arcsec or 6200 AU at 100 microns. The source is modeled using a radiative transport code to match scans of the source and previous photometry. The luminosity of the source is 520 solar at a distance of 390 pc. The optical depth at 100 microns is 0.20, implying a mass of 1.2-10 solar within a radius of 5900 AU. The density gradient is in good agreement with theoretical models for infalling envelopes around protostars and in reasonable agreement with other observational determinations.