Planetary Research. Publications

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O.M.Starodubtseva, L.A.Akimov, V.V.Korokhin, V.G.Tejfel (1994) SPATIAL AND TEMPORAL VARIATIONS OF THE DEGREE OF LINEAR POLARIZATION FOR JUPITER IN THE VISIBLE SPECTRAL RANGE. Kinematika Fizika Nebeshykh Tel, 1994, v.10, No 2, pp.50-57

Polarimetric observations of Jupiter were carried out using different technique and different telescopes during apparitions of 1981, 1985, 1986 and 1989. Distributions of the linear polarization degree along the central meridian for different longitudes were obtained. A significant increase in the degree of linear polarization in polar regions was confirmed. Polarization increases abruptly from latitudes 40 degree N and 47 degree S toward the poles. The north-south asymmetry in the degree of polarization measured in polar regions is revealed: the polarization in north polar region within the 5-6 of arcsec is larger than in south polar region at the same latitudes. At low latitudes, the degree of linear polarization correlates with the zone-belt structure. The data for 1989 show the asymmetry in the phase angle dependence of polarization measured at north and south hemispheres. Variations of polarization degree in polar regions with the central meridian longitude reveal systematic annual shift of modulation phase in the System III longitude and stable characteristics of modulation in the System IY.

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O.M.Starodubtseva, L.A.Akimov, V.V.Korokhin (1997-1) TIME VARIATIONS OF NORTH-SOUTH DISSYMMETRY IN THE POLARIZED EMISSION OF JUPITER. Astronomicheskii Vestnic, 1997, v.31, No 3, pp.214-221 [Solar System Research (Engl. transl.), 1997, v.31, No 3, pp. - ]

Polarimetric observations of Jupiter were carried out during eight apparitions of the planet from 1981 to 1995. All data, except those obtained in the summer of 1994, exhibit a north-south dissymmetry in the polarized emission of Jupiter. Until 1994, the polarization degree was greater in hight latitudes of the northern hemisphere than in the same latitudes of the southern hemisphere. In 1994, the dissymmetry was not observed almost at all.In 1995, the polarization was higher in the southern hemisphere. The cause of the north-south dissymmetry is unknown. However, the change in the chacter of the dissymetry which was observed between 1993 and 1995 could be related to the effect of the visit of comet Shoemaker-Levy 9 to the Jovian system. The possibility of correlation between dissymmetry changes and the magnetic solar-activity cycle also cannot be ruled out.

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O.M.Starodubtseva, L.A.Akimov, V.V.Korokhin (1997-2) TEMPORAL CHANGES IN THE NORTH-SOUTH ASYMMETRY OF POLARIZED LIGHT OF JUPITER MAY BE ASSOCIATED WITH THE COMET SL9 VISIT TO THE JOVIAN SYSTEM. Planetary and Space Science, 1997, v.45, No 10, pp.1183-1188

Polarimetric observations of Jupiter at blue wavelengths were taken during the comet SL9 collision with the planet and compared with seven other observations made during the period from 1981 to 1995. The data show temporal variations in the north-south asymmetry of polarization at high latitudes. Before 1993 - 1994 the polarization degree near the north limb is greater than that for the symmetrical regions near the south limb. In the July 1994 data the difference between the polarization degrees at north and south vanished. The observations of 1995 show the degree of polarization at south latitudes to be greater than that at the same north latitudes. These changes may be related to the increase of dust abundance in the magnetosphere and stratosphere of Jupiter owing to the comet SL9 visit to the Jovian system. However, correlation between temporal variations of the polarization asymmetry and the magnetic solar cycle cannot be ruled out.

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Rosenbush V.K., Kiselev N.N., Jockers K., Korokhin V.V., Shakhovskoy N.M., and Efimov Yu.S. Optical polarimetry of the Galilean satellites, Iapetus, and 64 Angelina near opposition // Kinematics and Physics of Celestial Bodies. Supplement Series . - 2000, No3, -p. 227-230.

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Starodubtseva O.M., Akimov L.A., Korokhin V.V. Seasonal variations in the N/S asymmetry of polarized light of Jupiter // Lunar and Planet. Sci. 31-th. Abstract #1095. 2001. LPI. Houston.

Seasonal changes in the north-south asymmetry of polarization at high latitudes of Jupiter are revealed from polarimetric observations in blue light made over a 18yr period. They are seemingly caused by seasonal north-south asymmetry in solar radiation incident on Jupiter's atmosphere.

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Starodubtseva O.M., Akimov L.A., Korokhin V.V. Seasonal variation to the North-South asymmetry of polarized light of Jupiter // Icarus.-2002. v.157, No2, -p.419-425.

Seasonal changes in the north-south asymmetry of polarization at high latitudes of Jupiter have been revealed from polarimetric observations in the blue light made over 18-year period. The average seasonal difference in the polarization degree between north and south is positive and equal to about 0.5%. There is some relationship between seasonal variations in the observed difference and the seasonal north-south asymmetry in solar radiation incident on Jupiter's atmosphere. There are two maxima on observed seasonal curve falling on the jovian spring and autumn and coinciding correspondingly with positive and negative maxima of heliographic latitude of Jupiter. Two possible explanations are discussed: seasonal changes in insolation and/or time-dependent magnetospheric influence on the polar events.