Optical spectroscopy and photometry of main-belt asteroids with a high orbital inclination

TL;DR

This study conducted optical spectroscopy on 51 main-belt asteroids, mainly with high orbital inclinations, revealing a higher fraction of D-type asteroids among them and suggesting their formation and perturbation history.

Contribution

First spectroscopic survey focusing on high-inclination main-belt asteroids, identifying their spectral types and comparing D-type fractions with low-inclination counterparts.

Findings

8 asteroids classified as D-type

D-type fraction is higher in high-inclination asteroids

Some D-type asteroids formed between the main belt and Jupiter

Abstract

We carried out low-resolution optical spectroscopy of 51 main-belt asteroids, most of which have highly-inclined orbits. They are selected from D-type candidates in the SDSS-MOC 4 catalog. Using the University of Hawaii 2.2 m telescope and the Inter-University Centre for Astronomy and Astrophysics 2 m telescope in India, we determined the spectral types of 38 asteroids. Among them, eight asteroids were classified as D-type asteroids. Fractions of D-type asteroids are 3.0+/-1.1 for low orbital inclination main-belt asteroids and 7.3+/-2.0 for high orbital inclination main-belt asteroids. The results of our study indicate that some D-type asteroids were formed within the ecliptic region between the main belt and Jupiter, and were then perturbed by Jupiter.