NGC 3132 In The Constellation Vela (Eight Burst Neb.)

ASTRONOMY PICTURE OF THE DAY: NOVEMBER 10, 1998

Explanation: It's the dim star, not the bright one, near the
center of NGC 3132 that created this odd but beautiful
planetary nebula. Nicknamed the Eight-Burst Nebula and the
Southern Ring Nebula, the glowing gas originated in the outer
layers of a star like our Sun.
In this representative color picture, the hot blue pool of light
seen surrounding this binary system is energized by the hot
surface of the faint star. Although photographed to explore
unusual symmetries, it's the asymmetries that help make
NGC 3132 so intriguing. Neither the unusual shape of the
surrounding cooler shell nor the structure and placements
of the cool filamentary dust lanes running across NGC 3132
are well understood.
Credit: Hubble Heritage Team (AURA/ STScI/ NASA)

 

ADS Astronomy Abstract Service
Title:
HST/WFPC2 Observations of Asymmetric Planetary and Proto-Planetary Nebulae:
NGC3132, Hen 401 and Roberts 22
Authors: SAHAI, R.; TRAUGER, J.; BUJARRABAL, V.; WFPC2 ID TEAM
Affiliation: AA(JPL/Caltech), AC(Observatorio Astronomico Nacional, Spain)
Journal: American Astronomical Society Meeting, 191, #15.08
Publication Date:12/1997
Origin: AAS
Abstract Copyright: (c) 1997: American Astronomical Society
Bibliographic Code: 1997AAS...191.1508S

Abstract

As part of a continuing effort to understand how planetary nebulae acquire their complex shapes and symmetries, we have obtained high-resolution images of the planetary nebula NGC3132, and the proto-planetary nebulae Hen 401 and Roberts 22, with the Wide Field Planetary Camera 2 (WFPC2) aboard the Hubble Space Telescope (HST). The images have been taken through a variety of narrow emission-line filters and a medium or broad continuum filter. All 3 objects have substantial quantities of cold, dense molecular gas detected via mm-wave CO line emission. The Hubble images reveal a
rich and complex morphological structure of the circumstellar material in these objects.

The NGC3132 images show a bright elliptical shape, surrounded by fainter filamentary, elliptical structures with position angles different from the main structure. New features uncovered by HST in this well-observed (from the ground) extended nebula, include a wide pillar-like structure lying roughly along the major axis of the nebula in [OIII]lambda5007 and Halpha , but not in the low-excitation [OI]lambda6300 & [NII]lambda6584 lines. The latter show a thin equatorial band of material girdling the main nebula around its waist, and a fine jet-like feature extending radially outwards from the equatorial girdle. Both protoplanetary nebulae, Hen 401 and Roberts 22, seen mostly in scattered light from dust, are bipolar. The bipolar lobes in Hen 401 are long and cylindrical (length/width~14), with frayed ends; the visible central star is surrounded by a bipolar skirt-like structure, co-axial with the lobes. In Roberts 22, the lobes are shaped like a butterfly's wings, separated by a dark ``body'' of dense dust which hides the central star, and multiple shell structures can be seen in the fainter nebulosity surrounding the main lobes. We will discuss the implications of the remarkable structures seen in these 3 nebulae for current theories for the formation and shaping of planetary nebulae.