Colors and taxonomy of Centaurs and trans-Neptunian objects

Abstract

Context. The study of the surface properties of Centaurs and trans-Neptunian objects (TNOs) provides essential information about the early conditions and evolution of the outer Solar System. Due to the faintness of most of these distant and icy bodies, photometry currently constitutes the best technique to survey a statistically significant number of them. Aims. Our aim is to investigate color properties of a large sample of minor bodies of the outer Solar System, and set their taxonomic classification. Methods. We carried out visible and near-infrared photometry of Centaurs and TNOs, making use, respectively, of the FORS2 and ISAAC instruments at the Very Large Telescope (European Southern Observatory). Using G-mode analysis, we derived taxonomic classifications according to the Barucci et al. (2005a, AJ, 130, 1291 system. Results. We report photometric observations of 31 objects, 10 of them have their colors reported for the first time ever. 28 Centaurs and TNOs have been assigned to a taxon. Conclusions. We combined the entire sample of 38 objects taxonomically classified in the framework of our programme (28 objects from this work; 10 objects from DeMeo et al. 2009a, A&A, 493, 283) with previously classified TNOs and Centaurs, looking for correlations between taxonomy and dynamics. We compared our photometric results to literature data, finding hints of heterogeneity for the surfaces of 4 objects.

A portrait of the extreme solar system object 2012 DR30

“…9), although this is not hugely surprising, given the remarkably small uncertainties in the orbit of the object. Nevertheless, this result is reassuring, in that it tells us that the dynamical behaviour we observe for the object is truly representative, in Perna et al 2010), and the TNOs Eris (purple curve Alvarez-Candal et al 2011) and Makemake (dark blue curve Brown et al 2007). In addition, the average reflectivities of the S-and V-type asteroids are also shown (green and orange curves, respectively, Chapman et al 1993;Gaffey et al 1993).…”

“…A-type asteroids have similar reflectance spectra due to olivine (DeMeo et al 2009). (2005); blue triangles with errors bars correspond to the mean values of the BB, BR, RI and RR taxonomy classes of TNOs and Centaurs (Perna et al 2010), from bottom-left to top-right, respectively; the green and orange points show the median colours of the olivine bearing S-type and V-tpye asteroids, respectively (Chapman et al 1993). The big black open circle marks the solar colours (Ramírez et al 2012).…”

“TNOs are Cool”: A survey of the trans-Neptunian region

“…We use 10 scan legs in each map, separated by 4 . The length (Perna et al 2010, and references therein). Class.…”

“…comm. ); ( j) Grundy et al (2008); (k) Perna et al (2010); (m) Peixinho et al (2004); (n) Sheppard & Jewitt (2002); (o) Belskaya et al (2003); (p) Sheppard (2007); (q) Tegler & Romanishin (1998); (r) Jewitt & Luu (1998); (s) Barucci et al (1999); (t) Tegler et al (2003); (u) Trujillo & Brown (2002); (v) Boehnhardt et al (2002); (w) Tegler (2011, priv. comm.…”

Organic materials in planetary and protoplanetary systems: nature or nurture?

“…A taxonomic scheme based on multivariate statistics of the photometric color was proposed by Barucci et al (2005): four classes were identified indicating different composition and/or evolutional history, with increasingly red colors from the BB (blue objects) to the RR class (reddest objects). The relationship between taxonomical and dynamical classifications has been investigated in detail (Perna et al 2010) yielding somewhat inconclusive results. No direct correlation between color and dynamical parameters (in particular semi-major axis) was found.…”