Vestoids, Part II: The basaltic nature and HED meteorite analogs for eight Vp-type asteroids and their associations with (4) Vesta

Paul S. Hardersen, Vishnu Reddy, Rachel Roberts

(Submitted on 22 Oct 2015)

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“Improving constraints on the abundance of basaltic asteroids in the main asteroid belt is necessary for better understanding the thermal and collisional environment in the early solar system, for more rigorously identifying the genetic family for (4) Vesta, for determining the effectiveness of Yarkovsky/YORP in dispersing asteroid families, and for better quantifying the population of basaltic asteroids in the outer main belt (a greater than 2.5 AU) that are likely unrelated to (4) Vesta.
NIR spectral observations in this work were obtained for the Vp-type asteroids (2011) Veteraniya, (5875) Kuga, (8149) Ruff, (9147) Kourakuen, (9553) Colas, (15237) 1988 RL6, (31414) Rotaryusa, and (32940) 1995 UW4 during August and September 2014 utilizing the SpeX spectrograph at the NASA Infrared Telescope Facility (IRTF), Mauna Kea, Hawaii. Spectral band parameter (band centers, Band Area Ratios) and mineralogical analysis (pyroxene chemistry) for each average asteroid NIR reflectance spectrum suggests a howardite-eucrite-diogenite (HED) meteorite analog for each asteroid. (5875) Kuga is most closely associated with the eucrite meteorites, (31414) Rotaryusa is most closely associated with the diogenites, and the remaining other six asteroids are most closely associated with the howardite meteorites. Along with orbital locations in the inner main belt and in the vicinity of (4) Vesta, the existing evidence suggests that these eight Vp-type asteroids are also likely Vestoids. “