PRIMASS near-infrared study of the Erigone collisional family

Harvison, Brittany; De Prá, Mário; Pinilla-Alonso, Noemí; Lorenzi, Vania; de León, Julia; Morate, David; Licandro, Javier; Arredondo, Anicia; Campins, Humberto
Bibliographical reference

Icarus

Advertised on:
4
2024
Journal
Number of authors
9
IAC number of authors
3
Citations
0
Refereed citations
0
Description
Past analyses of spectral properties of the inner-belt primitive families in visible wavelengths have uncovered the possible existence of two compositional groups: Erigone-like (highly hydrated) and Polana-like (nearly anhydrous) (Morate et al., 2018). We explore the spectral properties of the Erigone asteroid family in the near-infrared to probe this hypothesis. To get a closer look at the family, we observed 25 family members over an observational campaign from 2014b-2016b utilizing the NASA Infrared Telescope Facility and the Telescopio Nazionale Galileo. The objects are analyzed by determining the taxonomic classification and spectral gradient values. The spectral gradient results display a compact, primarily reddened range of values in agreement with the primitive types identified through taxonomic classification. Erigone is found to be composed of C- and X-complex types as well as various end-members (L- and T-types). All objects classified as C-complex belong to either Ch- or Cgh-types, types that exhibit hydration in the visible region, aligning with the results of the Erigone family being highly hydrated. We find that trends pointing at the existence of Erigone-like and Polana-like groups in the visible do not appear in the analysis of the near-infrared data. An additional analysis of the Lucy mission target, (52246) Donaldjohanson, was performed and determined to be a probable true member of the Erigone family. Understanding the distribution and extent of hydration in the main asteroid belt contributes to understanding the solar system's evolution. It provides insight into the implications of primitive bodies being a possible source of Earth's water.