Earth, Moon, and Planets

, Volume 78, Issue 1–3, pp 5–11 | Cite as

Long-term Evolution of the Outgassing of Comet Hale-Bopp From Radio Observations

  • N. Biver
  • D. Bockelée-Morvan
  • P. Colom
  • J. Crovisier
  • B. Germain
  • E. Lellouch
  • J. K. Davies
  • W. R. F. Dent
  • R. Moreno
  • G. Paubert
  • J. Wink
  • D. Despois
  • D. C. Lis
  • D. Mehringer
  • D. Benford
  • M. Gardner
  • T. G. Phillips
  • M. Gunnarsson
  • H. Rickman
  • A. Winnberg
  • P. Bergman
  • L. E. B. Johansson
  • H. Rauer
Article

Abstract

C/1995 O1 (Hale-Bopp) has been observed on a regular basis since August 1995 at millimetre and submillimetre wavelengths using IRAM, JCMT, CSO and SEST radio telescopes. The production rates of eight molecular species (CO, HCN, CH3OH, H2CO,H2S, CS, CH3CN,HNC) have been monitored as a function of heliocentric distance(rh from 7 AU pre-perihelion to 4 AU post-perihelion. As comet Hale-Bopp approached and receded from the Sun, these species displayed different behaviours. Far from the Sun, the most volatile species were found in general relatively more abundant in the coma. In comparison to other species, HNC, H2CO and CS showed a much steeper increase of the production rate with decreasing rh. Less than 1.5 AU from the Sun, the relative abundances were fairly stable and approached those found in other comets near 1 AU.

The kinetic temperature of the coma, estimated from the relative intensities of the CH3OH and CO lines, increased with decreasing rh, from about10 K at 7 AU to 110 K around perihelion. The expansion velocity of the gaseous species, derived from the line shapes, also increased with a law close torh 3.

Comets C/1995 O1 (Hale-Bopp) radio observations molecules 

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References

  1. Biver, N., Rauer, H., Despois, D. et al.: 1996, ‘Substantial Outgassing of CO from Comet Hale-Bopp at Large Heliocentric Distance’, Nature 380, 137–139.CrossRefADSGoogle Scholar
  2. Biver, N., Bockelée-Morvan, D., Colom, P. et al.: 1997, ‘Evolution of the Outgassing of Comet Hale-Bopp (C/1995 O1) from Radio Observations’, Science 275, 1915–1918.CrossRefADSGoogle Scholar
  3. Bockelée-Morvan, D., Crovisier, J., Colom, P., and Despois, D.: 1994, ‘The Rotational Lines of Methanol in Comets Austin 1990 V and Levy 1990 XX’, Astron. Astrophys. 287, 647–665.ADSGoogle Scholar
  4. Bockelée-Morvan D., Moreno, R., Biver, N. et al.: 1996, ‘Comet C/1995 O1 (Hale-Bopp)’, IAU Circular No. 6511.Google Scholar
  5. Colom, P., Crovisier, J., Bockelée-Morvan, D., Despois, D., and Paubert, G.: 1992, ‘Formaldehyde in Comets I. Microwave Observations of P/Brorsen-Metcalf (1989 X), Austin (1990 V) and Levy (1990 XX)’, Astron. Astrophys. 264, 270–281.ADSGoogle Scholar
  6. Colom, P., Gérard, E., Crovisier, J. et al.: 1997, ‘Observations of the OH Radical in Comet C/1995 O1 (Hale-Bopp) with the Nançay Radio Telescope’, Earth, Moon, and Planets 78, 37–43.CrossRefADSGoogle Scholar
  7. Crovisier, J.: 1994, ‘Photodestruction Rates for Cometary Parent Molecules’, J. Geophys. Res. 99– E2, 3777–3781.CrossRefADSGoogle Scholar
  8. Crovisier, J., Biver, N., Bockelée-Morvan, D. et al.: 1995, ‘Carbon Monoxide Outgassing from Comet P/Schwassmann–Wachmann 1’, Icarus 115, 213–216.CrossRefADSGoogle Scholar
  9. Enzian, A., Cabot, H., and Klinger, J.: 1998, ‘Simulation of the Water and Carbon Monoxide Production Rates of Comet Hale-Bopp Using a Quasi 3-D Nucleus Model’, Planet. Space Sci. 46, 851–858.CrossRefADSGoogle Scholar
  10. Irvine, W. M., Dickens, J. E., Lovell, A. J. et al.: 1997, ‘The HNC/HCN Ratio in Comets’, Earth, Moon, and Planets 78, 29–35.CrossRefADSGoogle Scholar
  11. Jewitt, D., Senay M. and Matthews H.: 1996, ‘Observations of Carbon Monoxide in Comet Hale-Bopp’, Science 271, 1110–1113.ADSGoogle Scholar
  12. Meier, R., Eberhardt, P., Krankowsky, D., and Hodges, R. R.: 1993, ‘The Extended Formaldehyde Source in Comet Halley’, Astron. Astrophys. 277, 677–690.ADSGoogle Scholar
  13. Rodgers, S. D. and Charnley, S. B.: 1998, ‘HNC and HCN in Comets’, Astrophys. J. Lett. 501, L227–L230.CrossRefADSGoogle Scholar
  14. Wink, J., Bockelée-Morvan D., Despois, D. et al.: 1997, ‘Evidences for Extended Sources and Temporal Modulations in Molecular Observations of C/1995 O1 (Hale-Bopp) at the IRAM Interferometer’, Earth, Moon, and Planets 78, 63.CrossRefADSGoogle Scholar
  15. Womack, M., Festou, M. C., and Stern, S. A.: 1997, ‘The Heliocentric Evolution of Key Species in the Distantly-Active Comet C/1995 O1 (Hale-Bopp)’, Astron. J. 114, 2789–2795.CrossRefADSGoogle Scholar
  16. Woodney, L. M., A'Hearn, M. F., McMullin, J., and Samarasinha, N.: 1997, ‘Sulfur Chemistry at Millimeter Wavelengths in C/Hale-Bopp’, Earth, Moon, and Planets 78, 69–70.CrossRefADSGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • N. Biver
    • 1
  • D. Bockelée-Morvan
    • 1
  • P. Colom
    • 1
  • J. Crovisier
    • 1
  • B. Germain
    • 1
  • E. Lellouch
    • 1
  • J. K. Davies
    • 2
  • W. R. F. Dent
    • 2
  • R. Moreno
    • 3
  • G. Paubert
    • 3
  • J. Wink
    • 4
  • D. Despois
    • 5
  • D. C. Lis
    • 6
  • D. Mehringer
    • 6
  • D. Benford
    • 6
  • M. Gardner
    • 6
  • T. G. Phillips
    • 6
  • M. Gunnarsson
    • 7
  • H. Rickman
    • 7
  • A. Winnberg
    • 8
  • P. Bergman
    • 8
  • L. E. B. Johansson
    • 8
  • H. Rauer
    • 9
  1. 1.Observatoire de Paris-MeudonFrance
  2. 2.Joint Astronomy CentreUSA
  3. 3.Institut de Radio Astronomie MillimétriqueGranadaSpain
  4. 4.Institut de Radio Astronomie MillimétriqueGrenobleFrance
  5. 5.Observatoire de BordeauxFrance
  6. 6.CaltechUSA
  7. 7.Uppsala Astronomiska ObservatoriumSweden
  8. 8.Onsala Space ObservatorySweden
  9. 9.Institut für PlanetenerkundungDLRBerlinGermany

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