Mineralogy of Asteroid 1459 Magnya and implications for its origin

Detailed near-infrared spectral observations of Asteroid 1459 Magnya reveal an asteroid that is primarily composed of pyroxene and plagioclase feldspar, confirming earlier suggestions that Magnya has a basaltic composition. The average Magnya spectrum for March 23, 2002 has a Band I center of 0.926 mum and a Band II center of 1.938 mum. Observations over 4(1)/(2) hours show little variation in band center positions. The feldspar-to-pyroxene ratio is similar to 0.6 on Magnya's surface. Comparing Magnya with the spectral parameters from 4 Vesta shows discordant pyroxene chemistries; Magnya's pyroxenes contain similar to 10 mol% less Fs than Vesta's pyroxenes. This suggests that Magnya originated from a parent body other than 4 Vesta and that its progenitor formed in a more chemically reduced region of the solar nebula within the asteroid belt. (C) 2003 Elsevier Inc. All rights reserved.