Updated Taxonomy of Trans-neptunian Objects and Centaurs

Updated taxonomy of trans-neptunian objects and centaurs: Influence of albedo

Authors:

Belskaya et al

Abstract:

We present updated classification of 258 trans-neptunian objects (TNOs) and centaurs based on their visible and near-infrared colors. With increasing quality and quantity of color measurements we distinguished again four classes of objects confirming the previous classification into the BB, BR, IR, and RR taxonomic groups. Increasing accuracy of color measurements results in smaller scatter on color–color plots and better separation of classes. Albedos do not have any noticeable impact on the classification except for the separation of a sub-group of the brightest bodies inside the BB group. On the other side, all the BR objects for which albedo estimations are available have dark surfaces, while the IR and RR groups contain objects both with dark and moderate albedos. Analysis of the distribution of the groups with respect to their orbital parameters confirmed previous findings. The BB and RR groups are populated mainly with classical objects having generally high or low orbital inclinations, respectively. Any centaur belongs to the IR group and only one centaur is classified as BB: this is a confirmation of the existence of two separate classes in this population.