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Title: ULTRAVIOLET SPECTRA OF THE C-2003K7 COMET: EVIDENCE FOR DUST SUBLIMATION IN Si AND C LINES

Journal Article · · Astrophysical Journal Letters
 [1];  [2]
  1. INAF-Osservatorio Astronomico di Palermo, P.za Parlamento 1, 90134 Palermo (Italy)
  2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

UV spectra of the bright sungrazing comet C-2003K7 detected at 2.37 R {sub sun} above the Sun surface by the Ultraviolet Coronagraph Spectrometer (UVCS) during the daily synoptic scan show bright lines of H I Ly{alpha}, Si III {lambda} 1206, and C III {lambda} 977. The derived outgassing rate is an order of magnitude larger than those of the other sungrazers observed by UVCS. Analysis of the spectra suggests that the comet broke apart into smaller pieces before it reached the UVCS slit. The observations provide lower and upper limits to the values of the Si III/C III ratio, in the range 8-22. The ratio indicates a larger abundance of silicates in the cometary dust as compared to organic refractory materials.

OSTI ID:
21305043
Journal Information:
Astrophysical Journal Letters, Vol. 713, Issue 1; Other Information: DOI: 10.1088/2041-8205/713/1/L69; Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English