Bulletin of Taras Shevchenko National University of Kyiv. Astronomy, no. 58, p. 6-10 (2018)
Spectrophotometrical researches of the subnuclear area of 46P/WIRTANEN comet
V. Ponomarenko, PhD.
K. Chiuryumov, Dr. Sci., Prof.
O. Sergeev, Cand. Tech. Sci.
Astronomical Observatory of Taras Shevchenko National University of Kyiv, Kyiv
Abstract
The observations and research of the short-period comet 46P/Wirtanen by optical spectra with an average resolution (λ/Δλ ≈ 1400) are presented. Spectra in January 2008 at the Peak Terskol mountain observatory with the Zeiss-2000 telescope (D = 2.0 m; F2 = 16 m) were obtained. On the basis of the received spectral material, the identification of emission bands was carried out. The distribution of the total energy flux, reflected energy flux and the spectrophotometric gradient in the spectral range λλ = 4850–7650 ÅÅ are constructed. The quality of the received spectral material allowed estimating with high accuracy the gas productivity of the molecules C2, NH2 and the relative dust productivity in cometary filters GC, RC. The relative dust productivity (Afρ), the gas productivity (Q) for the molecular emissions of C2 and NH2, as well as some other physical parameters of the neutral gas cometary atmosphere were evaluated. The resulting values of physical quantities are characteristic for Jupiter family comets. The gas productivity of 46P/Wirtanen during the observation period QC2 = 3.97–4.12 × 1025 mol/s, QNH2 = 2.06–2.97 × 1025 mol/s. The obtained values of gas and dust productivity characterize the cometary coma of 46P/Wirtanen as dust-rich. In comparison with the data of 1998, a significant decrease in production in the atmosphere of the comet of the NH2 molecule was recorded. The spectrophotometric gradient obtained for comet Wirtanen is characteristic for other JFC and is 8.6 % per 1000 Å. The relative dust productivity (Afρ) at the time of observations in January 2008 was significantly higher than in previous passages of perihelion. The obtained results may be the consequence of evolution of the upper layers of the cometary nucleus and require further experimental confirmation.
Key words
Comets, spectrophotometry, dust/gas productivity
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