2009/09/30 by D. Jones, M. Lloyd, D. L. Mitchell +3 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Bipolar nebula #Emission nebula #Emission spectrum #Nebula #Planetary nebula #Protoplanetary nebula #Spectral line #Stellar, planetary, and galactic studies #Torus #astro-ph.SR
paper · pdf · doi:10.1111/j.1365-2966.2009.15650.x
published as 2010, MNRAS, 401, 405 · 7 pages, 4 figures. Accepted for publication in MNRAS
openalex publication_date 2009/10/19 · arxiv created 2009/12/04 · arxiv updated 2011/11/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the first detailed spatio-kinematical analysis and modelling of the southern planetary nebula SuWt 2. This object presents a problem for current theories of planetary nebula formation and evolution, as it is not known to contain a central post-main-sequence star. Deep narrow-band [N ii]6584 Å images reveal the presence of faint bipolar lobes emanating from the edges of the nebular ring. Long-slit observations of the Hα and [N ii]6584 Å emission lines were obtained using the ESO (European Southern Observatory) Multi-Mode Instrument on the 3.6-m ESO New Technology Telescope. The spectra reveal the nebular morphology as a bright torus encircling the waist of an extended bipolar structure. By deprojection, the inclination of the ring is found to be 68°± 2° (cf. ∼90° for the double A-type binary believed to lie at the centre of the nebula), and the ring expansion velocity is found to be 28 km s−1. Our findings are discussed with relation to possible formation scenarios for SuWt 2. Through comparison of the nebular heliocentric systemic velocity, found here to be −25 ± 5 km s−1, and the heliocentric systemic velocity of the double A-type binary, we conclude that neither component of the binary could have been the nebular progenitor. However, we are unable to rule out the presence of a third component to the system, which would have been the nebula progenitor.