^1,2Lucas T.McClure,²Sean S.Lindsay
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2022.114907]
¹Department of Physics & Astronomy, The University of Tennessee, Knoxville, TN 37916, United States
²Northern Arizona University, Department of Astronomy and Planetary Science, Flagstaff, AZ 86011, United States
Copyright Elsevier

The visible and near-infrared spectra (0.5–2.5 μm) of ordinary chondrite (OC) meteorites are characterized by absorptions at 1 and 2 μm, typically denoted as Band I and Band II, respectively. Previous works have connected parameterization of Band I and Band II, a so-called band parameter analysis (BPA) of mineralogical abundances and chemistry of OC meteorites. In particular, parameters for these determinations include the center of the Band I feature (BIC) and band area ratio (BAR), the ratio of Band II’s area to that of Band I. Through treating BIC as a function of BAR, OCs plot within a region called the “OC-boot,” first shown in Gaffey et al. (1993). The boundaries for the OC-Boot have remained unchanged since their foundational work, and numerous investigations using various different methods have employed the same boundaries for the OC-Boot’s original zoning. By applying the Spectral Analysis Routine for Asteroids (SARA) to >150 spectra of OCs from Brown University’s NASA/Keck Reflectance Experiment Laboratory (RELAB) database, we highlight the issue of the OC-Boot’s dependency on BPAs. Namely, we vary how Band I and Band II are defined to highlight the BPA-dependency by producing band edge-specific OC-Boots that encompass the mineralogical diversity of OCs (H, L, and LL subtypes) with corresponding spectral ranges. We conclude that there is no single canonical OC-boot and suggest that researchers create their own OC-Boot using their specific BPA or select an OC-boot in the literature that most closely matches their methods of determining band parameters.