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PFP 1: A Large Annular Planetary Nebula Caught in the First Stages of ISM Interaction

M. J. Pierce·D. J. Frew·Q. A. Parker
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Abstract

This paper presents (H-alpha + [NII]) imaging and spectroscopy of a previously unknown, highly evolved planetary nebula of low excitation. It was discovered serendipitously from AAO/UKST H-alpha Survey images as part of a project to exploit the survey data and has evaded detection by previous surveys due to very low surface brightness. It is a remarkably annular planetary nebula, some 19' across, making it one of the largest examples of its type. We estimate a radius of 1.5 pc and a distance of 550pc as derived from a new H-alpha surface brightness - radius relation. PFP 1 has near perfect circular symmetry, broken only at the NW edge which is coupled with significantly increased (H-alpha + [NII]) intensity. This indicates an early stage of an interaction with the interstellar medium. A blue central star candidate has been identified from the SuperCOSMOS Sky Survey data.

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M. J. Pierce, D. J. Frew, Q. A. Parker. 2004-05-14. PFP 1: A Large Annular Planetary Nebula Caught in the First Stages of ISM Interaction. https://doi.org/10.1071/as04039

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