Spatial separation effect of asteroids with different albedos
  Numerical calculations of orbit evolutions of 1694 numbered asteroids included in the IRAS catalogue, from 13.11.1996 to 06.03.2006 were carried out. The values da - differences between the catalogue semimajor axes at 06.03.2006 and the calculated ones were computed. The average dependence da on albido p shows decrease of da at increase of p, and it is significant. In other words, semimajor axes of low-albedo asteroids are, on average, increasing as compared with high-albedo ones. Speed of such possible spatial separation for very dim and very bright asteroids of from 10 to 50km in order of magnitude is about 1 AU per 100 My. To explain this fact it may suppose an existence possibility of a non-gravitational effect. Such supposition is confirmed by distributions p(a) for asteroid families, above all, Flora family. An analysis of errors and residuals in the used asteroid catalogues is evidence of such supposition. 
A.M. Kazantsev (Kyiv National Taras Shevchenko University, Ukraine)