DATA_SET_DESCRIPTION |
Data Set Overview
=================
This dataset provides taxonomic classifications of asteroids in
each of six different systems: Tholen (1984, 1989) [THOLEN1984,
THOLEN1989]; Barucci, et al. (1987) [BARUCCIETAL1987]; Tedesco,
et al. (1989) [TEDESCOETAL1989]; Howell, et al. (1994)
[HOWELLETAL1994], Xu et al. (1995) [XUETAL1995], and Bus and
Binzel (2002) [BUS&BINZEL2002].
The data set contains entries for 1956 objects. Each of the six
taxonomies represented in this data set produced classifications
for a subset of these objects:
Tholen (1984, 1989) 978 objects
Barucci et al. (1987) 438 objects
Tedesco et al. (1989) 357 objects
Howell et al. (1994) 112 objects
Xu et al. (1995) 221 objects
Bus and Binzel (2002) 1447 objects
Asteroid taxonomy is the grouping of asteroids into a small number
of classes whose members have similar spectral reflectance
properties. The classification efforts prior to 1990 utilized
only the reflectivities between 0.3 and 1.1 microns for this
purpose (see Zellner et al. 1985 and Tedesco 1989); more
recently, infrared data extending to 2.5 microns were used for a
new classification scheme (Howell et al. 1994).
There are many different ways to perform this type of cluster
analysis, and the six different classifications tabulated in this
dataset represent six different algorithms developed during the
past twenty years (Tholen 1984, Barucci et al. 1987, Tedesco et
al. 1989, Howell et al. 1994, Xu et al. 1995, and Bus and Binzel
2002), as well as an extension of one of these algorithms to
additional objects (Tholen 1989, Mueller et al. 1992). These six
taxonomies have effectively replaced the older schemes used
previously. Detailed descriptions of each method can be found in
the corresponding references.
In this particular dataset, the six parameter fields indicate
which parameters were used to arrive at the classification for the
corresponding asteroid in each of the six taxonomies. A number
indicates the number of color indices utilized, the letter 'G'
indicates that a groundbased radiometric albedo was also utilized,
and the letter 'I' indicates that an IRAS radiometric albedo was
utilized. The letter 'A' indicates that an albedo of unspecified
source was used to eliminate some other possible classes based on
the spectrum alone. The letter 'S' indicates that the
classification is based on a medium resolution spectrum published
by Chapman and Gaffey (1979), while the higher resolution spectra
obtained by Xu et al. (1995) and Bus and Binzel (2002) are
indicated by a lowercase 's'. The Howell et al. (1994)
classifications are all based on a combination of 8-color (Zellner
et al. 1985) and 52-color (Bell et al. 1988) data, resampled at 65
points to provide more uniform wavelength sampling.
Five entries have a notation in the comment field regarding the
identification of the object. The details pertaining to each case
are in the column description for the comment field in the data
label.
References:
Barucci, M. A., M. T. Capria, A. Coradini, and M. Fulchignoni
1987. Classification of asteroids using G-mode analysis. Icarus
72, 304-324.
Bell, J. F., P. D. Owensby, B. R. Hawke, and M. J. Gaffey 1988.
The 52-color asteroid survey: Final results and interpretation.
Lunar Planet. Sci. Conf. XIX, 57.
Bowell, E., T. Gehrels, and B. Zellner 1979. Magnitudes, colors,
types, and adopted diameters of the asteroids. In Asteroids (T.
Gehrels, Ed.), pp. 1108-1129. Univ. of Arizona Press, Tucson.
Bus, S.J. and R.P. Binzel 2002. Phase II of the small main-belt
asteroid spectroscopic survey: A feature-based taxonomy. Icarus
158, 146-177.
Chapman, C. R., and M. J. Gaffey 1979. Reflectance spectra for
277 asteroids. In Asteroids (T. Gehrels, Ed.), pp. 655-687.
Univ. of Arizona Press, Tucson.
Howell, E. S., E. Merenyi, and L. A. Lebofsky 1994.
Classification of asteroid spectra using a neural network. J.
Geophys. Res. 99, 10847-10865.
Mueller, B. E. A., D. J. Tholen, W. K. Hartmann, and D. P.
Cruikshank 1992. Extraordinary colors of asteroidal object
(5145) 1992 AD. Icarus 97, 150-154.
Tedesco, E. F. 1989. Asteroid magnitudes, UBV colors, and IRAS
albedos and diameters. In Asteroids II (R. P. Binzel, T. Gehrels,
and M. S. Matthews, Eds.), pp. 1090-1138. Univ. of Arizona Press,
Tucson.
Tedesco, E. F., J. G. Williams, D. L. Matson, G. J. Veeder, J. C.
Gradie, and L. A. Lebofsky 1989. A three-parameter asteroid
taxonomy. Astron. J. 97, 580-606.
Tholen, D. J. 1984. Asteroid Taxonomy from Cluster Analysis of
Photometry. Ph.D. dissertation, University of Arizona.
Tholen, D. J. 1989. Asteroid taxonomic classifcations. In
Asteroids II (R. P. Binzel, T. Gehrels, and M. S. Matthews, Eds.),
pp. 1139-1150. Univ. of Arizona Press, Tucson.
Xu, S., R. P. Binzel, T. H. Burbine, S. J. Bus 1995. Small
main-belt asteroid spectroscopic survey: Initial Results.
Icarus 115, 1-35.
Zellner, B., D. J. Tholen, and E. F. Tedesco 1985. The
eight-color asteroid survey: Results for 589 minor planets.
Icarus 61, 355-416.
Modification History
====================
The asteroid taxonomy data set was first reviewed and ingested in
1993, and was updated in 1997 to include the neural net taxonomy
of Howell et al. (1994) [HOWELLETAL1994]. It was updated in 1999
to include the taxonomic classifications of the SMASS survey, Xu
et al. (1995) [XUETAL1995]. In 2002 it was updated to include the
classifications of the SMASSII survey, Bus and Binzel (2002)
[BUS&BINZEL2002].
Parameters
==========
The data table includes taxonomic classifications and the
parameters used to derived the classification in each of the
classification systems.
|