Laboratory of MSSB physics: scientific achievements

• The degree of linear polarization and its variation over cometary comae were measured at small phase angles for a group of the selected comets, which moves at large heliocentric distances (larger than 5 AU)
  10.1016/j.pss.2015.05.009
  10.1016/j.jqsrt.2017.10.002
• CO⁺ and N₂⁺ emissions were detected at such large heliocentric distances as 8.36 AU in the spectrum of comet C/2002 VQ94 (LINEAR):
  2014Icar..232...88K
  2008Icar..198..465K
• Based on the analysis of dynamic spectra of comet 1P/Halley, high amplitude (with a period of more than 1 hour) and low amplitude (with a period between 15 and 40 minutes) variations of the spectral line intensity were detected
  2002EM%26P...90..205B
• The spectral investigations of disintegrated comets have revealed the internal chemical inhomogeneity for both parent comet nuclei and its fragments
  1986Icar...66..230R
• Polarimetric data base was created and placed at NASA PLANETARY DATA SYSTEM
  pdssbn.astro.umd.edu/.../SUPPORT/dataset.html
  sbn.psi.edu/pds/resource/satpol.html
• Two groups of comets were distinguished based on the following parameters: the maximum of polarization degree, the temperature excess in the infra-red region, and the strength of 10 μm silicate emissions
  2007A%26A...463.1189K
• A group of the high albedo solar system bodies, which demonstrate a unique phenomenon - polarization opposition effect - was discriminated as a result of long lasting polarimetric observations made under extremely low phase angles
  1997ApJ...487..402R
  www.cambridge.org/.../11675B6A63E948C9A9266E78A7728C86
• The occurrence of non spherical dust particles in a cometary coma and its significant optical thickness was confirmed by spectral, photometric, and polarimetric observations of star occultations by cometary comae
  1997EM%26P...78..381R
  1994Icar..108...81R
  www.library.univ.kiev.ua.../astronom_47_2011.pdf
• Circular polarization of the comet light and its spacial distribution over a cometary coma was measured with high accuracy; the dependence of circular polarization degree on the solar phase angle was determined;
  2007Icar..186..317R
  2016MNRAS.462S.422K
• A group of comets with abnormal spectral dependence of polarization was found, the interrelation of physical and dynamic characteristics of these comets was identified
  2008JQSRT.109.1384K
  2000P%26SS...48.1005K
  2000EM%26P...82..141K
• The dependence of degree of linear polarization on solar phase angles and longitudes was determined for the Saturnian satellites Enceladus, Rhea, Dione, and Iapetus as well as for Uranus’ major satellites Miranda, Ariel, Unbriel, Titania, and Oberon
  2012P%26SS...73..407K
  2014AstBu..69..211A
  2015AASP....5...29Z
  2015KPCB...31..281Z

Theoretical findings

Main theoretical results are mostly described in the books written by L. M. Shulman "Comet nuclei" (1987, in russian) and "Dynamics of Cometary Atmospheres. Neutral gas " (1972, in russian). The development of ideas presented in these books promotes further research in the following areas:

• development of a physical model of the local areas of activity; possible ways of formation of active regions; the mechanisms and specific features of energy exchange and sublimation processes from local active centers;
• 3-D models based on the Monte-Carlo statistical method was developed; the model is used to describe the formation of dust tails and neutral comae as well as for the interpretation of observations of a number of comets, in particular the formation of strip structures;
• the internal sources of energy in cometary nuclei was investigated, the problems of heat capacity of water ice at low temperatures, sublimation of H₂O, CO, and CO₂ ices from the surface of a cometary nucleus, the transport of solar radiation through a dust coma with a nonlinear attenuation coefficient were studied;
• a few fundamentally new ideas were introduced in physics of comets. Among them is the theory of two-layered cometary nuclei, the idea of ion-molecular clusters as an internal source of energy in comet nuclei, the theory of crater formation at nucleus surface, theory of radiation transport through cometary comae.