J/A+A/707/A132 Taxonomic classification of asteroids (Pentikainen+, 2026)
Asteroid characterization using Gaia Data Release 3.
II. Taxonomic classification.
Pentikainen H., MacLennan E.M., Penttila A., Muinonen K., Oszkiewicz D.A.,
Cellino A., Tanga P., Wang X., Siltala L.
<Astron. Astrophys. 707, A132 (2026)>
=2026A&A...707A.132P 2026A&A...707A.132P (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Minor planets ; Spectroscopy ; Morphology
Keywords: minor planets, asteroids: general
Abstract:
We study the taxonomic classification of asteroids observed by Gaia as
a continuation of the lightcurve inversion work presented in Paper I
(MacLennan et al., 2026A&A...707A.131M 2026A&A...707A.131M, Cat. J/A+A/707/A131). We
examine the taxonomic classification of asteroids by using both Gaia
Data Release 3 (DR3) photometric and spectroscopic data. Particular
focus is placed on Ch-class asteroids, as their potentially hydrated
nature makes them promising candidates for sample-return missions and
the asteroid mining industry. We utilized the photometric slopes and
geometric albedos (via absolute magnitudes) derived from lightcurve
inversion, and the Gaia DR3 spectra (from 418nm to 770nm) as
classification parameters. We also considered how different parameter
sets affect classification accuracies for separate asteroid classes.
We classified the asteroids with a combination of linear discriminant
analysis and a nearest neighbor classifier. We achieve a
classification accuracy of 92% for known S-class asteroids and an
accuracy of 85% for Ch-class asteroids with a known set of 328
asteroids. Given the three classification parameters, tentative class
designations for 1668 previously unclassified asteroids are provided
in the Mahlke taxonomy. We also show that the photometric slope values
vary significantly within asteroid classes, with a standard deviation
three to four times the mean slope uncertainties. In conclusion, we
show that the combination of photometry and spectroscopy can be useful
in the taxonomic classification of asteroids observed by Gaia. Further
studies of the surface roughness at different scales could help
clarify the potential of the photometric slope in classification
efforts.
Description:
The file contains photometric slope and geometric albedo values and
tentative class designations for asteroids without a previous Mahlke
class.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
astclass.dat 43 1668 Results for individual asteroids
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See also:
B/astorb : Orbits of Minor Planets (Bowell+, 2014-)
J/A+A/707/A131 : Lightcurve inversion modeling with GaiaDR3 (MacLennan+, 2026)
Byte-by-byte Description of file: astclass.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- Number Asteroid number
10- 14 F5.3 mag/rad beta0 Photometric slope
18- 22 F5.3 mag/rad e_beta0 Uncertainty in the photometric slope
26- 30 F5.3 --- pGaia Geometric albedo using the Gaia filter
34- 38 F5.3 --- e_pGaia Uncertainty in the geometric albedo
42- 43 A2 --- Class Asteroid class in the Mahlke taxonomy
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Acknowledgements:
Hanna Pentikainen, hanna.pentikainen(at)helsinki.fi
References:
MacLennan et al., Paper I, 2026A&A...707A.131M 2026A&A...707A.131M, Cat. J/A+A/707/A131
(End) Hanna Pentikainen [Univ. Helsinki], Patricia Vannier [CDS] 08-Jan-2026