Surface Ice and Tholins on the Extreme Centaur 2012 DR<SUB>30</SUB>

DOI: 
10.3847/1538-3881/aab14e
Publication date: 
01/04/2018
Main author: 
Szabó, Gy. M.
IAA authors: 
Duffard, R.;Alvarez-Candal, A.
Authors: 
Szabó, Gy. M.;Kiss, Cs.;Pinilla-Alonso, N.;Hsiao, E. Y.;Marion, G. H.;Györgyey Ries, J.;Duffard, R.;Alvarez-Candal, A.;Sárneczky, K.;Vinkó, J.
Journal: 
The Astronomical Journal
Refereed: 
Yes
Publication type: 
Article
Volume: 
155
Pages: 
170
Abstract: 
2012 {DR}}<SUB>30</SUB> is one of the known solar system objects with the largest aphelion distance, exceeding 2200 au, on a high inclination orbit (i = 78°). It has been recognized to be either a borderline representative of high inclination, high perihelion distance (HiHq) objects, or even a new class of bodies, similar to HiHq objects for orbit but with an aphelion in the inner Oort Cloud. Here, we present photometry using long-term data from 2000 to 2013 taken by the SDSS sky survey, ESO MPG 2.2 m and McDonald 2.1 m telescopes, and a visual+near-infrared spectrum taken with the Southern Astrophysical Research Telescope and Magellan telescopes, providing insights into the surface composition of this body. Our best fit suggests that the surface contains 60% of complex organics (30% of Titan and 30% of Triton tholins) with a significant fraction of ice (30%, including pure water and water with inclusions of complex organics) and 10% silicates. The models also suggest a low limit of amorphous carbons, and hence the fragmentation of long-chained complex organics is slower than their rate of generation. 2012 {DR}}<SUB>30</SUB> just recently passed the perihelion, and the long-term photometry of the object suggested ambiguous signs of activity, since the long-term photometric scatter well exceeded the supposed measurement errors and the expected brightness variation related to rotation. Photometric colors put 2012 {DR}}<SUB>30</SUB> exactly between dark neutral and red objects, thus it either can be in a transition phase between the two classes or have differing surface properties from these populated classes.
Database: 
ADS
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2018AJ....155..170S/abstract
ADS Bibcode: 
2018AJ....155..170S
Keywords: 
Kuiper belt objects: individual: 2012 DR30