The statistical analysis of the color—orbit parameters and color—inclination distributions of TNOs

Abstract

The research of the surface properties of the trans-Neptunian Objects (TNOs) is the key factor to obtain information about past and current status of our Solar System. Because of the far distance from the Sun the photometric investigations remain the most popular approaching way to study of physical conditions of TNOs. For this reason, we examine the correlation between 294 known B-R and 259 V-R color indexes and the orbital parameters of the trans-Neptunian Objects (TNOs) with by classification is giving in the literature: Cubewanos (Classical KBOs), Plutinos, Sentaurs, SDOs, Other TNOs, and Resonants, and subgroups by diameters greater than 80 km. Almost all inclinations of subgroups by classifications and diameters are strongly correlated with B-R and V-R indexes. Simultaneously, the remarkable and moderate correlations with high significance levels were found in 8 cases for B-R and other orbit parameters: semi-major axis, eccentricity, perihelion and diameters by diameter subgroups and 9 cases by classifications. Moreover, only 4 of 11 moderate correlation coefficients with high significance levels for V-R were calculated by classifications and 6 cases by diameters. On the contrary of previously researches, we have found a unimodal B-R color distribution for Cubewanos instead of bimodal distribution of TNOs. Every classification of TNOs has more than 2 color peaks—polymodal distribution and number of the peaks rises by increasing of observed TNOs. This claim contradicts the existence of sharp boundaries between “blue” and “red” objects. We explain this tendency by the interplanetary nano-dust, which surrounds Solar System and according to Rayleigh scattering the light from TNOs passing through the interplanetary nano-dust in case low-inclinations so-called “cold” objects seem more reddish, and high-inclinations so-called “hot” objects seem more bluish.