| Autor: |
C. E. Delahodde, Rita Schulz, M. Tarenghi, Richard M. West, Tomohiko Sekiguchi, Olivier Hainaut, H. Boehnhardt, R. Amestica, G. P. Tozzi, Jason Spyromilio, G. Schwehm |
| Předmět: |
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| Zdroj: |
Scopus-Elsevier |
| Popis: |
Comet 46P/Wirtanen, prime target of ESA's ROSETTA mission, was successfully observed at the Very Large Telescope Observatory in Chile: on 17 May 1999 with the Test Camera at the Cassegrain focus of the 8.2-m VLT Kueyen telescope and on 8 December 2001 with FORS1 at Unit Telescope 4 Yepun. May 1999: no coma was detected at heliocentric distance r = 4.98 AU. From the measured brightness in the Bessell R-filter, a mean nucleus radius of 555 ′ 40 m is derived (for a geometric albedo of 0.04 and a phase darkening of 0.04 mag/deg). The nucleus signal varies during the 2.7 h observing interval and a peak-to-peak amplitude of ∼0.38 mag is determined. The measured lightcurve is in agreement with a rotation period of 6-7.5 hours and a ratio of the main nucleus axes of at least 1.4. The non-detection of a coma allows one to put an approximate upper limit for Afp of |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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