NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
CO observations of candidates for carbon-rich asymptotic giant branch and post-asymptotic giant branch starsCircumstellar CO emission has been detected in a number of featureless or weak SiC emission, low color temperature IRAS sources. The CO detections confirm the suggestion that these are either extreme carbon stars, carbon-rich proto-planetary nebulae (PPNs), or carbon-rich planetary nebulae (PNs). We find that the CO emission is relatively stronger for a given luminosity in post-AGB stars than AGB stars, suggesting a more efficient excitation mechanism is at work in the post-AGB phase. One probable post-AGB star was detected in HCN for the first time. The available HCN data suggest a rapid decline in HCN emission after the AGB. Molecular emission is shown to be a useful tracer of the evolution from asymptotic giant branch to the planetary nebula phase.
Document ID
19930037553
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Volk, Kevin
(NASA Headquarters Washington, DC United States)
Kwok, Sun
(Calgary Univ. Canada)
Woodsworth, Andrew W.
(Dominion Astrophysical Observatory Victoria, Canada)
Date Acquired
August 16, 2013
Publication Date
January 1, 1993
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 402
Issue: 1
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
93A21550
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available