Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· On-line Data
· References in the article
· Citations to the Article (34) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (7)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
The Evolving Morphology of the Bipolar Nebula M2-9
Authors:
Doyle, Sean; Balick, Bruce; Corradi, R. L. M.; Schwarz, H. E.
Affiliation:
AA(Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 ), AB(Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195), AC(Instituto de Astrofísica de Canarias, Calle Vía Láctea, E-38200 La Laguna, Tenerife, Spain), AD(Nordic Optical Telescope, Apdo. 321, E-38780 Santa Cruz de la Palma, Spain)
Publication:
The Astronomical Journal, Volume 119, Issue 3, pp. 1339-1344. (AJ Homepage)
Publication Date:
03/2000
Origin:
UCP
Astronomy Keywords:
ISM: PLANETARY NEBULAE: GENERAL, ISM: PLANETARY NEBULAE: INDIVIDUAL: ALPHANUMERIC: M2-9, STARS: WINDS, OUTFLOWS
DOI:
10.1086/301267
Bibliographic Code:
2000AJ....119.1339D

Abstract

The planetary nebula M2-9 has drastically changed its shape since its discovery by Minkwoski. Although the outline of the nebula seems to be stationary, most of the knots and bright features (N1, N2, S1, and S2) have moved laterally from the west to the east edges of both lobes. These features and their changes have reflection, not point, symmetry. We have compiled high-quality CCD images in Halpha and [O III] obtained every 2-5 years since 1985 to monitor position and morphological changes in the individual knots. Our results show that the recent structural changes are more complex than suggested previously. The pattern of changes resemble a rotating corkscrew-like pattern, as if a precessing ionization/excitation beam inscribes the knots and filaments on the pencil-shaped lobe edges. The beam flow speed is no higher than 0.01c, so the beam is not a light beam. Its rotation period is about 120 yr. The corkscrew pattern and its apparent speed render many simple models implausible. The model of beads sliding along a helical wire is easily ruled out by observations. A model that may work is a combination of a beam and a spray of energetic particles, both invisible and moving radially at about 1000 km s-1, which shock-heats and ionizes the walls of the lobes as the beams precess.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
  New!

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints