Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1775273 | Icarus | 2007 | 9 Pages |
Abstract
The results of the 9P/Tempel 1 CARA (Cometary Archive for Amateur Astronomers) observing campaign is presented. The main goal was to perform an extended survey of the comet as a support to the Deep Impact (DI) Mission. CCD R, I and narrowband aperture photometries were used to monitor the AfÏ quantity. The observed behavior showed a peak of 310 cm 83 days before perihelion, but we argue that it can be distorted by the phase effect, too. The phase effect is roughly estimated around 0.0275 mag/degree, but we had no chance for direct determination because of the very similar geometry of the observed apparitions. The log-slope of AfÏ was around â0.5 between about 180-100 days before the impact but evolved near the steady-state like 0 value by the impact time. The DI module impact caused about a 60% increase in the value of AfÏ and a cloud feature in the coma profile which was observed just after the event. The expansion of the ejecta cloud was consistent with a fountain model with initial projected velocity of 0.2 km/s and β=0.73. Referring to a 25,000 km radius area centered on the nucleus, the total cross section of the ejected dust was 8.2/Akm2 0.06 days after the impact, and 1.2/Akm2 1.93 days after the impact (A is the dust albedo). Five days after the event no signs of the impact were detected, nor deviations from the expected activity referring both to the average pre-impact behavior and to the previous apparitions.
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Physical Sciences and Engineering
Earth and Planetary Sciences
Space and Planetary Science
Authors
G.A. Milani, Gy.M. Szabó, G. Sostero, R. Trabatti, R. Ligustri, M. Nicolini, M. Facchini, D. Tirelli, D. Carosati, C. Vinante, D. Higgins,