HST spectroscopic observations of Jupiter after the collision of comet Shoemaker-Levy 9

Science

Volumn 267, Issue 5202, 1995, Pages 1307-1313

  Noll, K S ^a   McGrath, M A ^a   Trafton, L M ^b   Atreya, S K ^c   Caldwell, J J ^d   Weaver, H A ^a   Yelle, R V ^e   Barnet, C ^d   Edgington, S ^c  

^a STScI   (United States)

^b UNIVERSITY OF TEXAS AT AUSTIN   (United States)

^c UNIVERSITY OF MICHIGAN   (United States)

^d Space Astrophysics Laboratory ^*  (Canada)

^e NASA AMES RESEARCH CENTER   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

SIO;

AMMONIA; CARBON DISULFIDE; IRON; MAGNESIUM; OXYGEN; SULFUR; WATER;

ARTICLE; ASTRONOMY; ATMOSPHERE; MICROCLIMATE; SPECTROSCOPY;

AMMONIA; ATMOSPHERE; CARBON DISULFIDE; EXTRATERRESTRIAL ENVIRONMENT; IRON; JUPITER; MAGNESIUM; OXYGEN; SOLAR SYSTEM; SPECTRUM ANALYSIS; SULFUR; SUPPORT, U.S. GOV'T, NON-P.H.S.; WATER;

EID: 0029633939     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.7871428     Document Type: Article

References (39)

1. We used the 0.86-arc sec diameter circular aperture with the FOS and the 1.74-arc sec square aperture with the GHRS. We used the Red digicon of the FOS. We analyzed FOS G190H data only longward of 1800 A because of scattered visible-wavelength photons within the FOS. The effective spectral resolution of our observations is 3.3 Å full width a t half maximum (FWHM) for the FOS with the G190H grating, 4.6 Å for the FOS G270H, 0.75 Å for the GHRS G270M, and 4.6 Å for the GHRS G140L. These values assume that the aperture was filled with an extended source of uniform brightness. Deviations from this ideal case almost certainly occurred, the most drastic being the 21 July observations with the FOS that began with a portion of the aperture off the limb. In such cases, the values quoted above are upper limits to the FWHM.
2. D. K. Yeomans et al., personal communication. The ephemerides were widely distributed via e-mail and were posted on the World Wide Web.
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13. 2 emission intensity of about 3.2 kR.
14. 2 emission intensity of about 3.2 kR.
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16. Abundances are reported as either line-of-sight column abundance, which takes into account the local emission angle and two-way path through the atmosphere, or vertical column abundance, a one-way column following the local normal vector.
17. Vibrational and rotational constants were obtained from R. F. Barrow and R. P. Du Parcq [Elemental Sulfur, B. Meyer, Ed. (Interscience, New York, 1965)]. Lifetimes and transition strengths are from K. A. Meyer and D. R. Crosley, J. Chem. Phys. 59, 1933 (1973); W. H. Smith, J. Quant. Spectrosc. Radiat. Transfer 9, 1191 (1969); and C. R. Quick and R. E. Weston, J. Chem. Phys. 74, 4951 (1981). Franck-Condon factors were obtained from W. R. Anderson, D. R. Crosley, J. E. Allen Jr., ibid. 71, 821 (1979).
18. Vibrational and rotational constants were obtained from R. F. Barrow and R. P. Du Parcq [Elemental Sulfur, B. Meyer, Ed. (Interscience, New York, 1965)]. Lifetimes and transition strengths are from K. A. Meyer and D. R. Crosley, J. Chem. Phys. 59, 1933 (1973); W. H. Smith, J. Quant. Spectrosc. Radiat. Transfer 9, 1191 (1969); and C. R. Quick and R. E. Weston, J. Chem. Phys. 74, 4951 (1981). Franck-Condon factors were obtained from W. R. Anderson, D. R. Crosley, J. E. Allen Jr., ibid. 71, 821 (1979).
19. Vibrational and rotational constants were obtained from R. F. Barrow and R. P. Du Parcq [Elemental Sulfur, B. Meyer, Ed. (Interscience, New York, 1965)]. Lifetimes and transition strengths are from K. A. Meyer and D. R. Crosley, J. Chem. Phys. 59, 1933 (1973); W. H. Smith, J. Quant. Spectrosc. Radiat. Transfer 9, 1191 (1969); and C. R. Quick and R. E. Weston, J. Chem. Phys. 74, 4951 (1981). Franck-Condon factors were obtained from W. R. Anderson, D. R. Crosley, J. E. Allen Jr., ibid. 71, 821 (1979).
20. Vibrational and rotational constants were obtained from R. F. Barrow and R. P. Du Parcq [Elemental Sulfur, B. Meyer, Ed. (Interscience, New York, 1965)]. Lifetimes and transition strengths are from K. A. Meyer and D. R. Crosley, J. Chem. Phys. 59, 1933 (1973); W. H. Smith, J. Quant. Spectrosc. Radiat. Transfer 9, 1191 (1969); and C. R. Quick and R. E. Weston, J. Chem. Phys. 74, 4951 (1981). Franck-Condon factors were obtained from W. R. Anderson, D. R. Crosley, J. E. Allen Jr., ibid. 71, 821 (1979).
21. Vibrational and rotational constants were obtained from R. F. Barrow and R. P. Du Parcq [Elemental Sulfur, B. Meyer, Ed. (Interscience, New York, 1965)]. Lifetimes and transition strengths are from K. A. Meyer and D. R. Crosley, J. Chem. Phys. 59, 1933 (1973); W. H. Smith, J. Quant. Spectrosc. Radiat. Transfer 9, 1191 (1969); and C. R. Quick and R. E. Weston, J. Chem. Phys. 74, 4951 (1981). Franck-Condon factors were obtained from W. R. Anderson, D. R. Crosley, J. E. Allen Jr., ibid. 71, 821 (1979).
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28. -1 at 1 AU for the CO (1-0) band for the quiet sun. The upper limit corresponds to the propagated error at the wavelength of the (1-0) band, which limits the detectability of features in Jupiter's dayglow spectrum, the local continuum for the CO emission bands. The effective width of the (1-0) band was taken to be the effective bandwidth, 2.1 Å. Extinction at the impact site may reduce the visibility of CO, leading to an underestimate of the atmospheric CO mole fraction. E. Lellouch et al. [Bull. Am. Astron. Soc., special session on comet Shoemaker-Levy 9, abstract 02.03] derive a CO mole fraction of ∼40 ppm for P ≤ 300 μbar, considerably higher than our upper limit.
29. -1 at 1 AU for the CO (1-0) band for the quiet sun. The upper limit corresponds to the propagated error at the wavelength of the (1-0) band, which limits the detectability of features in Jupiter's dayglow spectrum, the local continuum for the CO emission bands. The effective width of the (1-0) band was taken to be the effective bandwidth, 2.1 Å. Extinction at the impact site may reduce the visibility of CO, leading to an underestimate of the atmospheric CO mole fraction. E. Lellouch et al. [Bull. Am. Astron. Soc., special session on comet Shoemaker-Levy 9, abstract 02.03] derive a CO mole fraction of ∼40 ppm for P ≤ 300 μbar, considerably higher than our upper limit.
30. S. K. Atreya, Atmospheres and Ionospheres of the Outer Planets and their Satellites (Springer-Verlag, New York, 1987), chap. 3 and 5.
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33. G. Orton et al, Science 267, 1277 (1995).
34. H. P. Larson, D. S. Davis, R. Hofmann, G. L. Bjoraker, Icarus 60, 621 (1984).
35. K. Zahnle and M. Mac-Low, ibid. 108, 1 (1994).
36. J. S. Lewis and R. G. Prinn, Science 169, 472 (1970).
37. H. A. Weaver et al., Science 263, 787 (1994). An observational constraint on the size of the impactors comes from the upper limit diameter established by Weaver et al, of ∼4 km. Several theoretical arguments have led to estimates of diameter of ∼1 km for the parent object.
38. The Langhoff, personal communication.
39. 2, provided access to his spectroscopic library, and contributed many thoughtful ideas. D. Gilmore and E. Smith provided assistance at the cost of many hours of missed sleep. H. Hammel was a gracious negotiator in the competition for prime orbits during impact week and provided the images we needed for our initial target acquisition. R. Beebe and A. Simon helped us find the drifting impact sites in the weeks after the impacts. Everyone on the HST science observing team participated during impact week in an open and continuous exchange of ideas for which we are grateful. We also thank D. Leckrone for his enthusiastic support during the most harrowing parts of the impact week. M. A'Hearn and an anonymous referee provided valuable comments on the manuscript. Support provided by NASA through grant GO-5642.14-93 from the STSI, which is operated by the Association of Universities for Research in Astronomy under NASA contract NAS5-26555.