Presentation #212.01 in the session MBAs: Physical Characteristics (iPosters).
Within the inner main belt resides the Erigone asteroid family, which consists of roughly 1776 objects. One of these members is Donaldjohanson, the first target to be visited by the NASA Lucy Mission (the first fly-by mission to study the Trojan asteroids). Previous work done by Morate et al. (2016) combined visible photometry from SDSS and spectroscopy as a part of the PRIMitive Asteroids Spectroscopic Survey (PRIMASS) on a sample of 101 bodies. This study found that more than 87% of them belong to C, X, and B taxonomic groups, which confirms the initial classification of Erigone as a primitive family.
Here, we present work from an observational campaign (2014b - 2016b) using the Galileo National Telescope (TNG) and the NASA Infrared Telescope Facility (IRTF) to provide a wider viewing of the Erigone family in the near-infrared (0.8–2.5 microns). Our observations using the TNG and IRTF telescopes have produced near-infrared spectra of 26 objects that have now been reduced and taxonomically characterized. To characterize the spectra, we use Codes for ANalysis of Asteroids (CANA, De Prá et al. 2018) to associate a Bus-DeMeo taxonomical class and to provide the spectral gradient. To validate our taxonomical results, we use the MIT implementation of the Bus-DeMeo taxonomy. The results of the taxonomic classification align with what is known from the visible study; C-complex and X-complex types are prevalent with a contribution of D and L types. Alongside these types are a smattering of S-complexes, leading to the conclusion that interlopers exist within the available definition of the Erigone family (Nesvorny et al. 2015).
Analysis of the sample is ongoing, and our next step is to compare these objects to carbonaceous chondrite spectra from the NASA Reflectance Experiment Laboratory (RELAB) database. Furthering knowledge of the nature of collisional families is vital to understanding the beginning and evolution of the solar system. This is particularly so in the case of primitive asteroids, like Erigone family members, which are composed of the most pristine and untouched materials of the solar system.
Acknowledgements: We are thankful for the NASA IRTF and TNG telescopes for granting observational time for this study. We acknowledge partial support from NASA Grant 80NSSC18K0530 and from the Center for Luna and Asteroid Surface Science (CLASS) funded by NASA’s SSERVI program.