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Extending the McDonald Observatory Serendipitous Survey of UV/Blue Asteroid SpectraModerate resolution asteroid spectra in the 350 - 650 nm spectral range acquired randomly over many years (Cochran and Vilas, Icarus v 127, 121, 1997) identified absorption features in spectra of some of the asteroids. A feature centered at 430 nm was identified in the spectra of some low-albedo asteroids (C class and subclass), similar to the feature identified by Vilas et al. (Icarus, v. 102, 225,1993) in other low-albedo asteroid spectra and attributed to a ferric iron spin-forbidden transition in iron alteration minerals such as jarosite. Features at 505 nm and 430 nm were identified in the spectrum of 4 Vesta. The 505-nm feature is highly diagnostic of the amount and form of calcium in pyroxenes. This suggested further research on the sharpness and spectral placement of this feature in the spectra of Vesta and Vestoids (e.g., Cochran and Vilas, Icarus v. 134, 207, 1998). In 1997 and 1998, additional UV/blue spectra were obtained at the 2.7-m Harlan J. Smith telescope with a facility cassegrain spectrograph. These included spectra of low-albedo asteroids, the R-class asteroid 349 Dembowska, and the M-class asteroid 135 Hertha. These spectra will be presented and identified features will be discussed.
Document ID
20000084332
Document Type
Preprint (Draft being sent to journal)
Authors
Vilas, Faith (NASA Johnson Space Center Houston, TX United States)
Cochran, A. L. (Texas Univ. TX United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1999
Subject Category
Astronomy
Funding Number(s)
PROJECT: RTOP 344-32-50-02
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.