juliensimon/bus-demeo-asteroid-taxonomy

---
license: cc-by-4.0
pretty_name: "Bus-DeMeo Asteroid Taxonomy"
language:
- en
description: "Reference set of 371 asteroids with Bus-DeMeo spectroscopic taxonomic classifications, principal component scores, and spectral slopes. The standard taxonomy for asteroid composition studies, covering 24 classes based on visible and near-infrared reflectance spectra (0.45-2.45 um)."
task_categories:
- tabular-classification
tags:
- space
- asteroids
- taxonomy
- spectroscopy
- composition
- orbital-mechanics
- open-data
- tabular-data
size_categories:
- n<1K
configs:
- config_name: default
data_files:
- split: train
path: data/bus_demeo_asteroid_taxonomy.parquet
default: true
---

# Bus-DeMeo Asteroid Taxonomy

*Part of the [Astronomy Datasets](https://huggingface.co/collections/juliensimon/astronomy-datasets-69c24caf2f17e36128946743) collection on Hugging Face.*

The **Bus-DeMeo taxonomy** is the current standard classification system for asteroids based on
their visible and near-infrared reflectance spectra (0.45--2.45 um). This dataset contains the
**371** reference asteroids used to define and validate the taxonomy, each classified
into one of **31** taxonomic classes grouped into **13** complexes.

## Dataset description

The Bus-DeMeo system (DeMeo et al. 2009) extended the earlier Bus taxonomy into the near-infrared,
using principal component analysis on reflectance spectra to define 24 taxonomic classes. Each class
corresponds to distinct surface mineralogy: S-complex asteroids are silicate-rich (olivine/pyroxene),
C-complex are carbonaceous, X-complex have featureless spectra (metal-rich or enstatite), and
end-member types (V, A, D, K, etc.) have unique spectral signatures.

This dataset is the reference classification set -- the 371 asteroids whose spectra were
used to define and validate the taxonomy. It includes the taxonomic class, observation date,
spectral slope, and the five principal component scores from the PCA decomposition.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `asteroid_number` | int | IAU asteroid catalog number |
| `asteroid_name` | string | Asteroid name (e.g., "Ceres", "Vesta") |
| `provisional_designation` | string | MPC provisional designation |
| `taxonomic_class` | string | Bus-DeMeo class (e.g., S, C, Sq, Xk, V); 'w' suffix = slope >0.25; ':' = uncertain |
| `taxonomic_complex` | string | Broad grouping: S, C, X, or end-member letter |
| `obs_date` | date | Date of spectroscopic observation |
| `ref_code` | string | Literature reference code (a--i) |
| `spectral_slope` | float64 | Slope of the linear regression to the reflectance spectrum |
| `pc1` | float64 | First principal component score |
| `pc2` | float64 | Second principal component score |
| `pc3` | float64 | Third principal component score |
| `pc4` | float64 | Fourth principal component score |
| `pc5` | float64 | Fifth principal component score |

## Quick stats

- **371** asteroids in the reference taxonomy set
- **31** distinct taxonomic classes, **13** broad complexes
- Most common classes: S (102), Sw (42), L (22), Ch (18), Xk (17)
- **334** with IAU names, **371** with principal component scores

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/bus-demeo-asteroid-taxonomy", split="train")
df = ds.to_pandas()

# Class distribution
print(df["taxonomic_class"].value_counts())

# Complex distribution
print(df["taxonomic_complex"].value_counts())

# PC1 vs PC2 scatter plot colored by complex
import matplotlib.pyplot as plt
for cpx in ["S", "C", "X", "V"]:
sub = df[df["taxonomic_complex"] == cpx].dropna(subset=["pc1", "pc2"])
plt.scatter(sub["pc1"], sub["pc2"], label=cpx, alpha=0.6, s=15)
plt.xlabel("PC1")
plt.ylabel("PC2")
plt.legend()
plt.title("Bus-DeMeo Taxonomy: PC1 vs PC2 by Complex")
```

## Data source

DeMeo F.E., Binzel R.P., Slivan S.M., Bus S.J. (2009), "An extension of the Bus asteroid
taxonomy into the near-infrared", *Icarus*, 202, 160--180.
Accessed via [PDS Small Bodies Node](https://sbn.psi.edu/pds/resource/busdemeotax.html)
(urn:nasa:pds:ast.bus-demeo.taxonomy::1.0).

## Related datasets

- [neo-close-approaches](https://huggingface.co/datasets/juliensimon/neo-close-approaches) -- Near-Earth Object close approaches
- [asteroid-sbdb](https://huggingface.co/datasets/juliensimon/asteroid-sbdb) -- JPL Small-Body Database
- [meteorite-landings](https://huggingface.co/datasets/juliensimon/meteorite-landings) -- Meteorite Landings

## Pipeline

Source code: [juliensimon/space-datasets](https://github.com/juliensimon/space-datasets)

## Citation

```bibtex
@dataset{bus_demeo_asteroid_taxonomy,
author = {Simon, Julien},
title = {Bus-DeMeo Asteroid Taxonomy},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/bus-demeo-asteroid-taxonomy},
note = {Based on DeMeo et al. (2009, Icarus 202, 160) via PDS Small Bodies Node}
}
```

## License

[CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/)