ESTUDO DAS PROPRIEDADES FÍSICAS DE DUAS POPULAÇÕES DE PEQUENOS CORPOS: A DOS OBJETOS CRUZADORES DA ÓRBITA DE MARTE E A DE OBJETOS EM ÓRBITA PRÓXIMA DA TERRA

Abstract

The study of Mars-crossers (MCs) and near-Earth objects (NEOs) allows us to gather information about the Solar System’s smallest bodies due to their proximity to Earth. In this work, we present the results of photometric observations of 16 MCs and visible spectroscopic observations of 43 newly discovered NEOs. The NEO spectra were obtained during eighteen observing runs between October 2020 and December 2021, using the Goodman High Throughput Spectrograph at the 4.1-m Southern Astrophysical Research telescope (Cerro Pachón, Chile). We found a taxonomic distribution dominated by S-type asteroids, but with an overabundance of A- and D-types. This result aligns with recent studies on NEOs characterization and implies possible differences in the taxonomic distribution between “large” and “small” objects, emphasizing the notion of a non-homogeneous NEO population. Meanwhile, the sample of MCs was observed at the Observatório Astronômico do Sertão de Itaparica (Itacuruba, Brazil) between 2020, 2021, and 2022, using the 1.0-m telescope of the IMPACTON project. The objective was to obtain the complete photometric characterization, including the period of rotation, amplitude of the lightcurve, taxonomic class, absolute magnitude H, and G1 and G2 parameters. We determined the period of rotation for 6 objects, taxonomic classification for 11 objects, and constructed 14 phase curves. The taxonomic results revealed diversity in classes, and the analysis of the phase curves exhibited different trends when compared with other small body populations.