WorldCat Identities

Tholen, David J. (David James) 1955-

Overview
Works: 5 works in 10 publications in 1 language and 266 library holdings
Genres: Classification 
Roles: Author
Classifications: QB701, 523.482
Publication Timeline
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Most widely held works by David J Tholen
Pluto and Charon( Book )

4 editions published in 1997 in English and held by 185 WorldCat member libraries worldwide

Asteroid taxonomy from cluster analysis of photometry by David J Tholen( )

3 editions published in 1984 in English and held by 4 WorldCat member libraries worldwide

In the last few years, two major contributions to the asteroid database have been the eight-color and thermal radiometric surveys. The former consists of broad-band photometric measurements through eight filters spanning the 0.3 to 1.1 (mu)m wavelength range. The latter consists of thermal flux measurements at 10 and/or 20 (mu)m, and when combined with measures of the reflected light, can yield reliable estimates of their geometric albedos
ASTEROID TAXONOMY FROM CLUSTER ANALYSIS OF PHOTOMETRY by David J Tholen( )

in English and held by 0 WorldCat member libraries worldwide

In the last few years, two major contributions to the asteroid database have been the eight-color and thermal radiometric surveys. The former consists of broad-band photometric measurements through eight filters spanning the 0.3 to 1.1 μm wavelength range. The latter consists of thermal flux measurements at 10 and/or 20 μm, and when combined with measures of the reflected light, can yield reliable estimates of their geometric albedos. Visual display of the eight-color survey data can be simplified by reducing the dimensionality of the problem. A principal components analysis was performed to accomplish this task. The analysis shows that 95 percent of the information contained in the seven independent color indices is contained in two principal components. This result is due to the fact that most asteroid spectra can be explained in terms of two absorption features, one at ultraviolet and the other at near-infrared wavelengths. The photometric and radiometric data sets were also used, along with cluster analysis techniques, to produce an improved asteroid taxonomic system. Seven major classes are now recognized and are designated A, C, D, E, M, P, and S. Three interesting minor classes are also identified: B, F, and G. Marginal evidence for an eighth major class, here called T, exists in the data, but the reality of this class awaits confirmation by further observations of potential members. Three asteroids do not fall into any of the above classes and are assigned unique designations: R (349 Dembowska), Q (1862 Apollo), and V (4 Vesta). Four E-class asteroids are now known to exist in the main belt, yet nearly twice this number exist in or near the Hungaria region. Twenty eight D-class asteroids have been identified in the outer belt, where they represent a significant fraction of the population. Five D asteroids exist in the main belt, which one lying near the inner edge of the belt, which is dominated by S-class asteroids. Two of the interesting minor classes are
Observations of Planet Crossing Asteroids( )

1 edition published in 1999 in English and held by 0 WorldCat member libraries worldwide

This grant funds the investigation of the Solar System's planet crossing asteroid population, principally the near Earth and trans-Neptunian objects, but also the Centaurs. Investigations include colorimetry at both visible and near infrared wavelengths, light curve photometry, astrometry, and a pilot project to find near Earth objects with small aphelion distances, which requires observations at small solar elongations
 
Audience Level
0
Audience Level
1
  Kids General Special  
Audience level: 0.58 (from 0.56 for Pluto and ... to 0.94 for Observatio ...)

Alternative Names
David J. Tholen amerikansk astronom

David J. Tholen astronome américain

David James Tholen

David Tholen US-amerikanischer Astronom

Дэвид Джеймс Толен американский астроном

Դևիդ Տոլեն

Languages
English (10)

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