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A Speculation into the Origin of Neutral Globules in Planetary Nebulae: Could the Helix’s Comets Really be Comets?

Published online by Cambridge University Press:  25 April 2016

Grant Gussie
Grant Gussie*
Affiliation:
Department of Physics, University of Tasmania, GPO Box 252C, Hobart, Tas. 7001, Australia. Grant.Gussie@phys.utas.edu.au
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Abstract

A novel explanation for the origin of the cometary globules within NGC 7293 (the ‘Helix’ planetary nebula) is examined, namely that these globules originate as massive cometary bodies at large astrocentric radii. The masses of such hypothetical cometary bodies would have to be several orders of magnitude larger than those of any such bodies observed in our solar system in order to supply the observed mass of neutral gas. It is, however, shown that comets at ‘outer Oort cloud’ distances are likely to survive past the red giant and asymptotic giant branch evolutionary phases of the central star, allowing them to survive until the formation of the planetary nebula. Some observational tests of this hypothesis are proposed.

Keywords

planetary nebulae — ISMmolecular — comets
Type
Galactic and Stellar
Information
Publications of the Astronomical Society of Australia , Volume 12 , Issue 2 , August 1995 , pp. 170 - 173
Copyright
Copyright © Astronomical Society of Australia 1995

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References

Bar-Nun, A., Dror, J., Kovachavi, E., & Laufer, D., 1985, Icarus, 63, 317 Google Scholar
Bohlin, R., Harrington, J. P., & Stecher, T. P., 1982, ApJ, 255, 87 Google Scholar
Daub, C. T., 1982, ApJ, 260, 612 Google Scholar
Duncan, M., Quinn, T., & Tremaine, S., 1987, AJ, 94, 1330 Google Scholar
Dyson, J. E., Hartquist, T. W., Pettini, M., & Smith, L. J. 1989, ApJ, 260, 612 Google Scholar
Hawley, S. A., 1978, PASP, 90, 370 Google Scholar
Huggins, P. J., & Healy, A. P., 1986, AJ, 100, 511 Google Scholar
Huggins, P. J., Bachiller, R., Cox, P. Forveille, T., 1992, ApJ, 401, L43 Google Scholar
Hughes, D. W., 1991, MNRAS, 251, 26pGoogle Scholar
Intrilligator, D., & Dryor, M., 1991, Nature, 353, 407 Google Scholar
Kippenhahn, R., 1981, A&A, 102, 293 Google Scholar
Kouchi, A., Greenberg, J. M., Yamamoto, T., & Mukai, T., 1992, ApJ, 388, L73 Google Scholar
Kreysing, H. C., Diesch, C., Zweigle, J., Staubert, R., Grewing, M., & Hassinger, G., 1992, A&A, 264, 623 Google Scholar
Kwok, S., Purton, C. R., & Fitzgerald, M. P., 1978, ApJ, 247, L67 Google Scholar
Leahy, D. A., Zhang, C. Y., & Kwok, S., 1994, ApJ, 422, 205 Google Scholar
Meaburn, J., Walsh, J. R., Clegg, R. E. S., Walton, N. A., Taylor, D., & Berry, D. S., 1992, MNRAS, 255, 177 Google Scholar
Newburn, R. L. Jr., & Spinrad, H., 1989, AJ, 97, 552 CrossRefGoogle Scholar
Notesco, G., Kleinfeld, I., Lauffer, D., & Bar-Nun, A. 1991 Icarus, 63, 317 Google Scholar
Schmitt, B., Espinasse, S., Grim, R. J. A., Greenberg, J., & Klinger, J., 1989, Laboratory Studies of Cometary Ice Analogues, International Workshop on Physics and Mechanics of Cometary Materials, ESA SP-301, 65Google Scholar
Storey, J. W. V., 1984, MNRAS, 206, 521 Google Scholar
Vorontsov-Velyaminov, B. A. 1968, IAU Symp. 34, 256 Google Scholar
Walsh, J. R., & Meaburn, J., 1993, The Messenger, 73, 35 Google Scholar
Weissman, P. R., 1990, Nature, 344, 825 CrossRefGoogle Scholar
Weissman, P. R., 1991, Icarus, 89, 190 Google Scholar
Weissman, P. R., 1993, S&T, 85, 26 Google Scholar
West, R. M., Hainaut, O., & Smette, A., 1991, A&A, 246, L77 Google Scholar