POLARIMETRY AND PHOTOMETRY OF COMET-C 1996-B2-HYAKUTAKE

Polarimetric and photometric observations of Comet C/1996 B2 Hyakutake were carried out at the 70-cm telescope of Kharkov State University O bservatory from March 25 to April 7, 1996. The goal of the observation s was to determine the polarization maximum of the cometary continuum. We have found that the maximal degrees of polarization in the blue (4 845 Angstrom) and red (6840 Angstrom) continuum domains are 24.0% and 26.1%, respectively, and lie at a phase angle close to 94 degrees, sli ghtly dependent on wavelength. According to the gas-to-dust ratio and color, Comet Hyakutake belongs to the group of dusty comets such as We st 1976 VI, P/Churyumov-Gerasimenko 1982 VIII, P/Kopff 1983 XIII, P/Ha rtley-IRAS 1984 Iii, P/Giacombini-Zinner 1985 XIII, P/Halley 1986 III, Bradfield 1987 XXIX, Liller 1988 V, Levy 1990 XX, and P/Faye 1991 XXI . The polarization data for comet Hyakutake are in good agreement with the data for these comets in the 37 degrees-73 degrees overlap region of phase angles. Consequently, the maximum of Hyakutake's polarizatio n may be taken as the maximum of polarization at least of this group o f dusty comets. The fluxes for the C-2 and C-3 emission bands and dust continuum and the corresponding production rates for Comet Hyakutake are given. (C) 1998 Academic Press.