Preplanetary Nebulae: A Hubble Space Telescope Imaging Survey and a New Morphological Classification System

By R. Sahai, Mark R. Morris, C. Sánchez Contreras, M. Claussen. 2007

152 citations recorded by the source corpus.

Using the Hubble Space Telescope (HST), we have carried out a survey of candidate preplanetary nebulae (PPNs). We report here our discoveries of objects having well-resolved geometric structures, and we use the large sample of PPNs now imaged with HST (including previously studied objects in this class) to devise a comprehensive morphological classification system for this category of objects. The wide variety of aspherical morphologies which we have found for PPNs are qualitatively similar to those found for young planetary nebulae (PNs) in previous surveys. We also find prominent halos surrounding the central aspherical shapes in many of our objects; these are direct signatures of the undisturbed circumstellar envelopes of the progenitor AGB stars. Although the majority of these have surface brightness distributions consistent with a constant mass-loss rate with a constant expansion velocity, there are also examples of objects with varying mass-loss rates. As in our surveys of young PNs, we find no round PPNs. The similarities in morphologies between our survey objects and young PNs supports the view that the former are the progenitors of aspherical PNs. This suggests that the primary shaping of a PN does not occur during the PN phase via the fast radiative wind of the hot central star, but significantly earlier in its evolution.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/6a11620c7d502dc2b466e6a2a953b3b0a68b07be

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. H. Olofsson
2. I. Bojičić
3. S. Höfner
4. Q. Parker
5. D. Frew
6. Mark R. Morris
7. T. Alexander

In Instrumentation

1. I. Bojičić
2. Q. Parker
3. D. Frew
4. S. Höfner
5. H. Olofsson
6. Mark R. Morris

Citations in the corpus

• YOUNG PLANETARY NEBULAE: HUBBLE SPACE TELESCOPE IMAGING AND A NEW MORPHOLOGICAL CLASSIFICATION SYSTEM (2011, methodology): “…with the Hubble Space Telescope (HST), a comprehensive morphological classification scheme was recently developed for Pre-Planetary Nebulae (PPNs) (Sahai et al. 2007), We present here a generalization of our PPN classification scheme for young PNs and we show that this can be done with relatively…”
• Mass loss of stars on the asymptotic giant branch (2018, background): “The large majority of the proto-PNe and PNe are axially symmetric rather than spherical, a phenomenon that is more common among the younger objects (e.g., Sahai et al. 2007, 2011).”
• The Hα surface brightness–radius relation: a robust statistical distance indicator for planetary nebulae (2015, methodology): “For compact Galactic PNe, we utilised HST images if available, either from the literature (e.g. Sahai et al. 2007; Gesicki et al. 2014; Hsia et al. 2014) or from the Hubble Legacy Archive.7 The dimensions of compact PNe derived from ground-based measurements were corrected using a PSF deconvolution…”