Rotation of comet 46P/Wirtanen
1997; EDP Sciences; Volume: 326; Issue: 3 Linguagem: Inglês
ISSN
1432-0746
AutoresK. J. Meech, J. M. Bauer, O. Hainaut,
Tópico(s)Planetary Science and Exploration
ResumoWe have observed comet 46P/Wirtanen during 1996 June, August and November using the University of Hawai‘i 2.2m telescope. At the time of the observations, the comet was at heliocentric distances, r = 2.99, 2.53 and 1.83 AU. During the August run observations were made in order to search for light curve variations due to rotational modulation of the nucleus. The comet was active for all runs, and during 1996 August the coma extended>16′′ (1.8× 104 kmat the distance of the comet) at PA ≈ 325◦, and during 1996 November the coma extended >20′′ (2.5× 104 km at the distance of the comet) at PA≈ 75◦. The surface brightness profile exhibited a gradient slope of−1.6 and −1.4 in August and November, respectively, only slightly steeper than that expected by radiation pressure and phase angle effects alone.Using a phase-dispersionminimization technique, we find a possible rotation period near 7.6 hours. The color of the nucleus plus dust is B − V = 0.756 ± 0.009, V − R = 0.456 ± 0.009 and R − I = 0.366 ± 0.009 averaged over the three runs.
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