Evolution of planetary nebulae. III. Position-velocity images of butterfly-type nebulae

Journal Article · Wed Feb 01 04:00:00 EST 1989 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/114995· OSTI ID:6200361

Icke, V; Preston, H L; Balick, B

Observations of the motions of the shells of the planetary nebulae NGC 2346, NGC 2371-2, NGC 2440, NGC 6058, NGC 6210, IC 1747, IC 5217, J-320, and M2-9 are presented. These are all 'butterfly' type PNs, and show evidence for bipolar shocks. The observations are interpreted in terms of a fast spherical wind, driven by the central star into a quasi-toroidal envelope deposited earlier by the star, during its slow-wind phase on the asymptotic giant branch. It is shown that this model, which is a straightforward extension of a mechanism previously invoked to account for elliptical PNs, reproduces the essential kinematic features of butterfly PNs. It is inferred that the envelopes of butterflies must have a considerable equator-to-pole density gradient, and it is suggested that the origin of this asphericity must be sought in an as yet unknown mechanism during the AGB, Mira, or OH/IR phases of late stellar evolution. 28 references.

• Research Organization: Leiden Rijksuniversiteit, Sterrewacht (Netherlands); Iowa State Univ. of Science and Technology, Ames (USA); Washington Univ., Seattle (USA)
• OSTI ID: 6200361
• Journal Information: Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 97; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
FLUID MECHANICS
HYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
MORPHOLOGY
MOTION
NEBULAE
ORIGIN
PLANETARY NEBULAE
ROTATION
SHOCK WAVES
STAR EVOLUTION
STAR MODELS
STARS
STELLAR ACTIVITY
STELLAR WINDS