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A. Storrs, E. Wells (STScI), B. Zellner (Ga. Sou. U.), A. Stern, D. Durda (SwRI)
We present a mineralogical analysis of eight main belt asteroids imaged with the Hubble Space Telescope (HST). S type asteroids 8 Flora, 11 Parthenope, 29 Amphitrite, and 89 Julia, and C types 10 Hygiea, 54 Alexandra, 144 Vibilia, and 1220 Crocus (this last of unknown type) were observed with the Wide-Field/Planetary camera 2 (WFPC2) in 1996. The filters used define the continuum in the blue (F673N and F439W), as well as the width (F1042M) and depth (F953N) of the 1 micron silicate feature. These are the same as were used to image asteroid 4 Vesta in 1996 (Zellner et al. 1996) and some of this data is presented for comparison.
These asteroids are only marginally resolved in these images, and we attempt to improve the resolution as well as compensate for the factor of two change in the intrinsic point spread function with iterative image deconvolution. The results are encouraging-- each object is observed twice and features repeat between observations. Maximum Entropy restorations reveal no large markings (like the ``Olbers Regio'' on Vesta). This is explained by the smaller size of the bodies studied.
No companions to these objects have been detected down to a limit of seven magnitudes fainter than the primary body.
This research is based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract No. NAS5-26555.
--------------------------\hfil\break Binzel et al. 1997: Icarus vol. 128, pp. 95-103\hfil\break Zellner et al. 1996: BAAS vol. 28, p. 1100\hfil
The author(s) of this abstract have provided an email address for comments about the abstract: storrs@stsci.edu