J/A+A/711/A167 Taxonomy of 14 042 Gaia DR3 asteroids (Tinaut-Ruano+, 2026)
Taxonomy of 14 042 asteroids from Gaia DR3 reflectance spectra.
Tinaut-Ruano F., Carry B., Galinier M., Mahlke M., Sergeyev A.
<Astron. Astrophys. 711, A167 (2026)>
=2026A&A...711A.167T 2026A&A...711A.167T (SIMBAD/NED BibCode)
ADC_Keywords: Minor planets ; Morphology
Keywords: methods: data analysis - methods: observational -
methods: statistical - techniques: spectroscopic - catalogs -
minor planets, asteroids: general
Abstract:
Asteroid reflectance spectra provide key constraints on surface
composition. Gaia Data Release 3 (DR3) enables the study of 60 518
asteroids through near-ultraviolet (NUV) to visible reflectance
spectra.
Our aim is to classify asteroids using Gaia DR3 spectra and provide a
homogeneous taxonomical framework. Owing to systematics affecting Gaia
DR3 data, direct comparison with previous taxonomies has to be
performed with caution; therefore, we developed a classification
scheme tailored to Gaia and linked the resulting taxa to established
classes.
We selected the highest-quality spectra using Gaia DR3 quality flags
and applied uncertainty thresholds to mitigate spectral artifacts,
retaining over one-third of the original sample at the least noisy
wavelengths. To improve compositional discrimination, we included
albedo information, thus reducing the final sample to about one-fourth
of its initial size. We then iteratively applied dimensionality
reduction and clustering techniques to identify the spectral taxa.
We classified 14042 asteroids into 13 taxonomic classes: A, B, C, D,
E, F, G, K, L, M, P, S, and V, representing an increase in three
compared to the number of objects classified in previous spectral
classifications. The largest relative increase was found for the K
class. The inclusion of NUV wavelengths allowed the separation of B
and F types within the C complex and facilitated the identification of
G types. The dynamical distribution follows expected trends: S types
dominate the inner and middle main belt; C-complex asteroids are
prevalent in the outer main belt; and D types are prevalent beyond the
main belt.
We present a taxonomical classification of 14 042 asteroids based on
Gaia DR3 reflectance spectra. NUV coverage is critical for
disentangling primitive classes within the C complex. Although
artifacts in Gaia DR3 require caution when one is comparing median
spectra with other datasets, this classification provides a robust
reference for future Gaia releases with larger observed samples.
Description:
We classified the reflectance spectra of 14 042 Gaia DR3 asteroids.
However, this data release has some artifacts that require caution
when performing direct comparison with reference spectra obtained in
previous classifications. Thus, to classify Gaia DR3 we needed to
follow a process of clustering as if we were trying to build a new
taxonomy, and then relate clusters to known taxa. To achieve our
objective, we first cleaned the sample based on the quality of the
spectral bands, avoiding some of the artifacts related to the
signal-to-noise ratio. Then, we carried out an iterative process of
clustering that allowed us to find 13 taxa related to known taxa: A,
B, C, D, E, F, G, K, L, M, P, S, V. The total number of classified
objects is 14042 asteroids, which is the largest systematic
classification using spectral information.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
class.dat 8 60017 Classification
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See also:
I/359 : Gaia DR3 Part 5. Solar System (Gaia Collaboration, 2022)
Byte-by-byte Description of file: class.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- MPC [1/399767] Identification number in Gaia DR3
8 A1 --- Tax Classification in the paper (1)
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Note (1): Not all objects in Gaia DR3 are classified, just 14042; the rest are
blank. See more about methods and results in the paper.
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Acknowledgements:
From Fernando Tinaut-Ruano, ftinautruano(at)gmail.com
Thanks to Noemie el Bez Sebastien for checking the goodness of our
D-type asteroids, and Roberto Balossi for sharing his knowledge about
L-type families. This work has made use of data from the European
Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia),
processed by the Gaia Data Processing and Analysis Consortium (DPAC,
https://www.cosmos.esa.int/web/gaia/dpac/consortium). F.T-R thanks
CNRS for funding my postdoctoral program. This work was supported by
the Programme National de Planetologie (PNP) of CNRS-INSU co-funded
by CNES. This work used Virtual Observatory tools SsODNet (Berthier et
al. 2023) and TOPCAT (Taylor 2005). Thanks to the developers and
maintainers.
(End) Patricia Vannier [CDS] 14-Jul-2026