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

Journal Article · Wed Feb 01 00:00:00 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., Ames, IA (United States); Univ. of Washington, Seattle, WA (United States)
• OSTI ID: 6200361
• Journal Information: Astron. J.; (United States), Vol. 97
• Country of Publication: United States
• Language: English

Related Subjects

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