The Southern Crab from a New Perspective

Abstract

New Hubble Space Telescope images and Cerro Tololo Inter-American Observatory echelle spectra of the nebula around the symbiotic Mira Henize 2-104 are presented. The nebula consists of two nested hourglass-shaped structures and a collimated polar jet. Spatiokinematical modeling shows that all three outflows were ejected during approximately the same epoch, namely, about 5700 years ago, with the adopted distance of 4.4 kpc, in a mass-loss event unrelated to the present outburst. We present a tentative model in which the outer pair of lobes and jets are produced by a high-velocity outflow from the white dwarf companion to the Mira, while the inner, slowly expanding lobes are produced by the Mira wind itself. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.