Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-26T04:28:07.308Z Has data issue: false hasContentIssue false
  • English
  • Français

A Continuing Controversy: Has the Cometary Nucleus been Resolved?

Published online by Cambridge University Press:  12 April 2016

Zdenek Sekanina

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Barnard (1891) appears to have been the first to recognize the significance of systematic observations of comets at large distances from the sun. His successful tracing of two 1889 comets to heliocentric distances over 5 and even 6 a. u. caused him to notice that some of the short-period comets might be within the reach of the Lick Observatory’s 36-inch refractor throughout their entire orbits around the sun. Although it is clear nowadays that the short-period comets would be a good deal fainter at comparable distances than the two nearly parabolic comets referred to by Barnard, his original idea proved basically correct, except for the necessity of using photographic plates. Periodic Comet Encke was probably detected near aphelion during Barnard’s lifetime, in September 1913 (Barnard 1914a; Marsden and Sekanina 1974). Undisputed images of the comet just several days off aphelion were obtained in 1972 (Roemer 1972; McCrosky and Shao 1972).

Type
Part II
Information
International Astronomical Union Colloquium , Volume 25 , Issue Part2: The Study of Comets , 1976 , pp. 537 - 587
Copyright
Copyright © NASA 1976

References

Andrews, A. D. (1966). Periodic Comet Neujmin 1 (1966a). IAU Circ. No. 1959.Google Scholar
Banachiewicz, T. (1914). Lichtschwankungen des Kometen 1913c (Neujmin). Astron. Nachr. 196, 249–250.Google Scholar
Barnard, E. E. (1891). Comets 1889 I and II, and some suggestions as to the possibility of seeing the short-period comets at aphelion. Astron. J. 10, 67–68.CrossRefGoogle Scholar
Barnard, E. E. (1914a). Encke’s Comet. On the possibility of photographing the comet at all points in its orbit. Pop. Astron. 22, 607–610.Google Scholar
Barnard, E. E. (1914b). Neujmin’s Comet. Astron. Nachr. 196, 181–182.CrossRefGoogle Scholar
Barnard, E. E. (1915). Observations of Comet 1913c (Neujmin). Astron. J. 28, 137–141.Google Scholar
Belyaev, N. A. (1967). Orbital evolution of Comets Neujmin 2 (1916 II), Comas Sola (1927 III), and Schwassmann-Wachmann 2 (1929 I) over the 400 years from 1660 to 2060. Soviet Astron. 11, 366–373.Google Scholar
Bertaux, J. L., Blamont, J. E., and Festou, M. (1973). Interpretation of hydrogen Lyman-alpha observations of Comets Bennett and Encke. Astron. Astrophys. 25, 415–430.Google Scholar
Blamont, J., and Festou, M. (1974). La comète de Kohoutek (1973f) observée en lumière de résonance du radical oxhydrile OH. Comptes Rendus 278 (Sér. B), 479–484.Google Scholar
Carruthers, G. R., Opal, C. B., Page, T. L., Meier, R. R., and Prinz, D. K. (1974). Lyman alpha imagery of Comet Kohoutek. Icarus (in press).Google Scholar
Code, A. D. (1971). Comments on OAO observations of Comets 1969g and 1969i. Trans. IAU 14B, 124.Google Scholar
Delsemme, A. H. (1972). Vaporization theory and non-gravitational forces in comets. In L’Origine du Système Solaire, Proc. Symp. Centre National de la Recherche Scientifique, Nice, ed. by Reeves, H., pp. 305–310.Google Scholar
Delsemme, A. H. (1973). The brightness law of comets. Astrophys. Lett. 14, 163–167.Google Scholar
Delsemme, A. H., and Miller, D. C. (1971). Physico-chemical phenomena in comets. III. The continuum of Comet Burnham (1960 II). Planet. Space Sci. 19, 1229–1257.CrossRefGoogle Scholar
Delsemme, A. H., and Rud, D. A. (1973). Albedos and cross-sections for the nuclei of Comets 1969 DC. 1970 E and 1971 I. Astron. Astrophys. 28, 1–6. [Should be 1971 II.]Google Scholar
Feldman, P. D., Takacs, P. Z., Fastie, W. G., and Donn, B. (1974). Rocket ultraviolet spectrophotometry of Comet Kohoutek (1973f). Science 185, 705–707.CrossRefGoogle ScholarPubMed
Graff, K. (1914). Über die Helligkeitsabnahme des Kometen 1913c (Neujmin). Astron. Nachr. 196, 250–252.Google Scholar
Jeffers, H. M. (1956). Observations of comets and asteroids. Astron. J. 61. 380–382.CrossRefGoogle Scholar
Jones, T. J., and Morrison, D. (1974). Recalibration of the photometric/radiometric method of determining asteroid sizes. Astron. J. 79, 892–895.CrossRefGoogle Scholar
Keller, H. U., and Lillie, C. F. (1974). The scale length of OH and the production rates of H and OH in Comet Bennett (1970 H). Astron. Astrophys. 34, 187–196.Google Scholar
Kresàk, L. (1973). Short-period comets at large heliocentric distances. Bull. Astron. Inst. Czech. 24, 264–283.Google Scholar
Marsden, B. G. (1966). One hundred periodic comets. Science 155, 1207–1213.CrossRefGoogle Scholar
Marsden, B. G. (1968). Comets and nongravitational forces. Astron. J. 73, 367–379.CrossRefGoogle Scholar
Marsden, B. G. (1969). Comets and nongravitational forces. II. Astron. J. 74, 720–734.CrossRefGoogle Scholar
Marsden, B. G. (1971). Comets in 1970. Quart. J. Roy. Astron. Soc. 12, 244–273.Google Scholar
Marsden, B. G. (1972a). Comets in 1971. Quart. J. Roy. Astron. Soc. 13, 415–435.Google Scholar
Marsden, B. G. (1972b). Nongravitational effects on comets: The current status. In The Motion, Evolution of Orbits, and Origin of Comets, Proc. IAU Symp. No. 45, ed. by Chebotarev, G. A., Kazimirchak-Polonskaya, E. I., and Marsden, B. G., D. Reidel Publ. Co., Dordrecht, Holland, pp. 135–143.CrossRefGoogle Scholar
Marsden, B. G. (1973a). Private communication.Google Scholar
Marsden, B. G. (1973b). Comets in 1972. Quart. J. Roy. Astron. Soc. 14, 389–406.Google Scholar
Marsden, B. G. (1974a). Private communication.Google Scholar
Marsden, B. G. (1974b). Comets in 1973. Quart. J. Roy. Astron. Soc. (in press).Google Scholar
Marsden, B. G., and Sekanina, Z. (1973). On the distribution of “original” orbits of comets of large perihelion distance. Astron. J. 78, 1118–1124.CrossRefGoogle Scholar
Marsden, B. G., and Sekanina, Z. (1974). Comets and nongravitational forces. VI. Periodic Comet Encke 1786–1971. Astron. J. 79, 413–419.CrossRefGoogle Scholar
Marsden, B. G., Sekanina, Z., and Yeomans, D. K. (1973). Comets and nongravitational forces. V. Astron. J. 78, 211–225.CrossRefGoogle Scholar
Masursky, H., Batson, R. M., McCauley, J. F., Soderblom, L. A., Wildey, R. L., Carr, M. H., Milton, D. J., Wilhelms, D. E., Smith, B. A., Kirby, T. B., Robinson, J.C., Leovy, C. B., Briggs, G. A., Duxbury, T.C., Acton, C. H. Jr., Murray, B.C., Cutts, J. A., Sharp, R. P., Smith, S., Leighton, R. B., Sagan, C., Veverka, J., Noland, M., Lederberg, J., Levinthal, E., Pollack, J. B., Moore, J. T. Jr., Hartmann, W. K., Shipley, E. N., de Vaucouleurs, G., and Davies, M. E. (1972). Mariner 9 television reconnaissance of Mars and its satellites: Preliminary results. Science 175, 294–305.CrossRefGoogle ScholarPubMed
McCrosky, R. E., and Shao, C. Y. (1972). Periodic Comet Encke. IAU Circ. No. 2446.Google Scholar
Oort, J. H. (1950). The structure of the cloud of comets surrounding the solar system, and a hypothesis concerning its origin. Bull. Astron. Inst. Neth. 11, 91–110.Google Scholar
Opal, C. B., Carruthers, G. R., Prinz, D. K., and Meier, R. R. (1974). Comet Kohoutek: Ultraviolet images and spectrograms. Science 185, 702–705.CrossRefGoogle ScholarPubMed
Osterbrock, D. E. (1958). A study of two comet tails. Astrophys. J. 128, 95–105.CrossRefGoogle Scholar
Pereyra, Z. M. (1966). Periodic Comet Neujmin 1 (1966a). IAU Circ. No. 1963.Google Scholar
Pilcher, C. B., Ridgway, S. T., and McCord, T. B. (1972). Galilean satellites: Identification of water frost. Science 178, 1087–1089.CrossRefGoogle ScholarPubMed
Roemer, E. (1956). Observations of comets. Astron. J. 61, 391–394.CrossRefGoogle Scholar
Roemer, E. (1962). Activity in comets at large heliocentric distance. Publ. Astron. Soc. Pacific 74, 351–365.CrossRefGoogle Scholar
Roemer, E. (1965). Observations of comets and minor planets. Astron. J. 70, 397–402.CrossRefGoogle Scholar
Roemer, E. (1966). The dimensions of cometary nuclei. In Nature et Origine des Cometès, Proc. Coll. Int. Univ. Liège, pp. 23–28.Google Scholar
Roemer, E. (1972). Periodic Comet Encke. IAU Circ. Nos. 2435 and 2446.Google Scholar
Roemer, E. (1973a). Comet notes. Mercury 2, no. 4, 19–21.Google Scholar
Roemer, E. (1973b). Notes on Comet Kohoutek 1973f. Mercury 2, no. 5, 11.Google Scholar
Roemer, E. (1974). Comet Kohoutek (1973f). IAU Circ. No. 2671.Google Scholar
Roemer, E., and Lloyd, R. E. (1966). Observations of comets, minor planets, and satellites. Astron. J. 71, 443–457.CrossRefGoogle Scholar
Sekanina, Z. (1969). Dynamical and evolutionary aspects of gradual deactivation and disintegration of short-period comets. Astron. J. 74, 1223–1234.CrossRefGoogle Scholar
Sekanina, Z. (1971). A core-mantle model for cometary nuclei and asteroids of possible cometary origin. In Physical Studies of Minor Planets, Proc. IAU Colloq. No. 12, ed. by Gehrels, T, NASA SP-267, pp. 423–428.Google Scholar
Sekanina, Z. (1972a). A model for the nucleus of Encke’s Comet. In The Motion. Evolution of Orbits, and Origin of Comets, Proc. IAU Symp. No. 45, ed. by Chebotarev, G. A., Kazimirchak-Polonskaya, E. I., and Marsden, B. G., D. Reidel Publ. Co., Dordrecht, Holland, pp. 301–307.Google Scholar
Sekanina, Z. (1972b). Rotation effects in the nongravitational parameters of comets. In The Motion, Evolution of Orbits, and Origin of Comets, Proc. IAU Symp. No. 45, ed. by Chebotarev, G. A., Kazimirchak-Polonskaya, E. I., and Marsden, B. G., D. Reidel Publ. Co., Dordrecht, Holland, pp. 294–300.Google Scholar
Sekanina, Z. (1973). Existence of icy comet tails at large distances from the sun. Astrophys. Lett. 14, 175–180.Google Scholar
Sekanina, Z., and Miller, F. D. (1973). Comet Bennett 1970 II. Science 179, 565–567.CrossRefGoogle ScholarPubMed
Traub, W. A., and Carleton, N. P. (1974). A search for HJO and CH. in Kohoutek, Comet. Icarus (in press).Google Scholar
Van Biesbroeck, G. (1914). Beobachtungen der vier Herbstkometen des Jahres 1913. Astron. Nachr. 197, 85–88.CrossRefGoogle Scholar
Van Biesbroeck, G. (1930a). Observations of comets at the Yerkes Observatory. Astron. J. 40, 51–60.CrossRefGoogle Scholar
Van Biesbroeck, G. (1930b). The return of Comet 1913 III (Neujmin) in 1931. Astron. J. 40, 77–79.CrossRefGoogle Scholar
Van Biesbroeck, G. (1933). Observations of comets at the Yerkes Observatory. Astron. J. 42, 25–32.CrossRefGoogle Scholar
Van Biesbroeck, G. (1950). Observations of comets. Astron. J. 55, 53–60.CrossRefGoogle Scholar
Veverka, J. (1973). The photometric properties of natural snow and of snow-covered planets. Icarus 20, 304–310.CrossRefGoogle Scholar
Walker, M. F. (1958). Observations of Comets Bakharev-Macfarlaine-Krienke, 1955f, and Baade, 1954h. Publ. Astron. Soc. Pacific 70, 191–196.CrossRefGoogle Scholar
Whipple, F. L. (1950). A comet model. I. The acceleration of Comet Encke. Astrophys. J. 111, 375–394.CrossRefGoogle Scholar
Whipple, F. L. (1962). On the distribution of semimajor axes among comet orbits. Astron. J. 67, 1–9.CrossRefGoogle Scholar