MCDONALD OBSERVATORY 9P/TEMPEL 1 DATA V1.0

We report on low-spectral resolution observations of comet 9P/Tempel 1 from 1983, 1989, 1994 and 2005 using the 2.7m Harlan J. Smith telescope of McDonald Observatory. This comet was the target of NASA's Deep Impact mission and our observations allowed us to characterize the comet prior to the impact. In the published paper, we showed that the comet decreased in gas production from 1983 to 2005, with the decrease being different factors for different species. OH decreased by a factor 2.7, NH by 1.7, CN by 1.6, C3 by 1.8, CH by 1.4 and C2 by 1.3. Despite the decrease in overall gas production and these slightly different decrease factors, we found that the ratios of the gas production rates of OH, NH, C3, CH and C2 that of CN were constant over all of the apparitions. We saw no change in the production rate ratios after the impact. We found that the peak gas production occurred about two months prior to perihelion. This data set represents the integrated fluxes and column densities, mentioned in the published paper, which were used to derive the production rates in the paper.

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Additional Info

Field Value
Maintainer Planetary Data System
Last Updated September 15, 2026, 00:18 (UTC)
Created March 9, 2026, 21:50 (UTC)
accessLevel public
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harvest_source_id b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title Science Discovery Engine
identifier urn:nasa:pds:context_pds3:data_set:data_set.ear-c-lcs-5-9ptmpl1-spectra-v1.0;urn:nasa:pds:context_pds3:data_set:data_set.ear-c-lcs-5-9ptmpl1-spectra-v1.0::1.0
license https://www.usa.gov/government-works
modified 2026-09-07T22:16:00Z
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publisher Small Bodies
resource-type Dataset
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