Presentation #114.04 in the session MBAs: Physical Characteristics, Part 1.
European Space Agency’s Gaia mission was launched in December 2013. It operates in the Lagrangian L2 point with the main goal of creating a 3-dimensional map of our Galaxy by surveying more than a thousand million stars. The current third data release DR3 includes, for the first time, the mean reflectance spectra of 60 518 asteroids at visible wavelengths (0.374μm – 1.05μm), which is a 10-fold increase in the number of known asteroid spectra.
We perform analysis of the spectral measurements obtained by the Gaia mission. First we use machine learning methods (gradient boosting, suport vector machine and multilayer perceptron network) to carry out a binary classify of the DR3 spectra into V-types and other-types. We achieved from 91 to 92% balanced accuracy. We then perform spectral analysis of the classified spectra.
We identified a number new V-type asteroids beyond 2.5 AU and a few in the Phocaea region. Most of these require further ground-based follow-up due to low quality spectra. We confirm that the V-type asteroids in the mid- and outer part of the main belt show distinct spectral properties compared to typical Vestoids. In the inner Main-belt, we found a great diversity of spectral parameters among the V-types in all populations. Number of them show band depths even greater than that of (1459) Magnya (Figure 1). Furthermore, some objects show the 0.9μm band-centers outside typical vestoidal values. These findings should be confirmed by independant ground-based observations in the full VISNIR wavelength range followed up by mineralogical analysis.