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The problem of the 1/a-distribution and cometary fading

Published online by Cambridge University Press:  12 April 2016

M.E. Bailey
M.E. Bailey*
Affiliation:
Department of Astronomy, University of Manchester, Manchester M13 9PL, England

Abstract

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The background to the problem of explaining the frequency distribution of cometary 1/a-values is briefly reviewed and it is emphasised that the explanation in terms of the Oort Cloud model relies on an ad hoc fitting function - the fading/disruption probability per revolution. Assuming an underlying steady-state Oort Cloud and the integral equation formalism developed by Oort and Yabushita to predict the 1/a-distribution for an arbitrary fading probability, we have been able to constrain the unknown fading function by comparison with observations. In agreement with previous work we find that the tendency for fading or disruption should be strong at small 1/a-values and weak at large 1/a-values. The mean fading probability per revolution, k(x), is found to lie within a factor roughly of order 2 about k(x) ≈ 0.3(1+(x/4 × 10−3)2)−3/2, where × is 1/a in units AU−1. A physical model for fading which might qualitatively account for this behaviour is tentatively proposed. This depends on the thermal shock experienced by a long-period comet nucleus around perihelion passage. It is emphasised that until a viable model for fading has been found, the validity of the steady-state primordial hypothesis remains unresolved.

Type
Section V. Dynamics of Comets
Information
International Astronomical Union Colloquium , Volume 83: Dynamics of Comets: Their Origin and Evolution , 1985 , pp. 311 - 317
Copyright
Copyright © Cambridge University Press 1985

References

Bailey, M.E., 1983. Mon. Not. R. astr. Soc., 204, 603.CrossRefGoogle Scholar
Bailey, M.E., 1984. Observatory, 104, 65.Google Scholar
Bailey, M.E., 1985. Mon. Not. R. astr. Soc., in press.Google Scholar
Bobrovnikoff, N.T., 1929. Lick Obs. Bull., 14, 28.Google Scholar
Crommelin, A.C.D., 1910. Rivista di Scienza, 7, 241.Google Scholar
Dobrovol#x2019;ski, O.V., 1972. IAU Symp., 45, 352.Google Scholar
Everhart, E., 1979. IAU Symp., 81, 273.Google Scholar
Everhart, E., 1982. In Comets, Wilkening, L.L. (ed), IAU Coll., 61 659.CrossRefGoogle Scholar
Everhart, E. and Marsden, B.G., 1983. Astr. J., 88, 135.CrossRefGoogle Scholar
Fernandez, J.A., 1981. Astr. Astrophys., 96, 26.Google Scholar
Giauque, W.F. and Stout, J.W., 1936. J. Amer. Chem. Soc, 58, 1144.CrossRefGoogle Scholar
Greenberg, J.M., 1982. In Comets, Wilkening, L.L. (ed), IAU Coll., 61, 131.CrossRefGoogle Scholar
Klinger, J., 1975. J. Glaciol., 14, 517.CrossRefGoogle Scholar
Lapiace, P.S., 1805. Mech. Celeste, 4, 193.Google Scholar
Laplace, P.S., 1816. Additions a la Connaissance des Temps, 213.Google Scholar
Marsden, B.G., Sekanina, Z. and Everhart, E., 1978. Astr. J., 83, 64.CrossRefGoogle Scholar
Newton, H.A., 1878. Amer. J. Sci. Arts, 16, 165.CrossRefGoogle Scholar
Oort, J.H., 1950. Bull. Astron. Inst. Neth., 11, 91.Google Scholar
Öpik, E.J., 1932. Proc Amer. Acad. Arts Sci., 67, 169.CrossRefGoogle Scholar
Richter, N.B., 1963. In The Nature of Comets, Methuen, London.Google Scholar
Russell, H.N., 1935. In The Solar System and its Origin, p. 43, New York.Google Scholar
Shtejns, K.A., 1972. IAU Symp., 45, 347.Google Scholar
Van Woerkom, A.J.J., 1948. Bull. Astron. Inst. Neth., 10, 445.Google Scholar
Weissman, P.R., 1979. IAU Symp., 81, 277.Google Scholar
Weissman, P.R., 1980. Astr. Astrophys., 85, 191.Google Scholar
Whipple, F.L., 1953. In La Physique des Cometes, Proc. 4th Coll. Int. d’Astrophys. Liege, p. 283.Google Scholar
Whipple, F.L., 1962. Astr. J.,67, 1.CrossRefGoogle Scholar
Yabushita, S., 1983. Mon. Not. R. astr. Soc., 204, 1185.CrossRefGoogle Scholar