2000/10/12 by Mario Livio, Noam Soker · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Asymptotic giant branch #Emission nebula #Nebula #Orbital period #Planetary nebula #Planetary system #Stellar evolution #Stellar, planetary, and galactic studies #Symbiotic star #White dwarf #astro-ph
paper · pdf · doi:10.1086/320567
13 pages + 2 figures. Submitted to ApJ
arxiv created 2000/10/12 · openalex publication_date 2001/05/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a model for the structure, temporal behavior, and evolutionary status of the bipolar nebula M2-9. According to this model, the system consists of an asymptotic giant branch (AGB) or post-AGB star and a hot white dwarf companion, with an orbital period of about 120 yr. The white dwarf has undergone a symbiotic nova eruption about 1200 yr ago, followed by a supersoft X-ray source phase. The positional shift of the bright knots in the inner nebular lobes is explained in terms of a revolving ionizing source. We show that the interaction between the slow, AGB star's wind and a collimated fast wind from the white dwarf clears a path for the ionizing radiation in one direction, while the radiation is attenuated in others. This results in the mirror-symmetric (as opposed to the more common point-symmetric) shift in the knots. We show that M2-9 provides an important evolutionary link among planetary nebulae with binary central stars, symbiotic systems, and supersoft X-ray sources.