---
license: cc0-1.0
pretty_name: "Nebula Catalog"
language:
  - en
description: "Catalog of nebulae sourced from Wikidata, covering emission, reflection, dark, and planetary nebulae across the sky.  Nebulae are clouds of interstellar gas and dust -- the birthplaces of stars, the r"
task_categories:
  - tabular-classification
tags:
  - space
  - astronomy
  - nebulae
  - deep-sky
  - wikidata
  - open-data
  - tabular-data
  - parquet
size_categories:
  - 10K<n<100K
configs:
  - config_name: default
    data_files:
      - split: train
        path: data/nebulae.parquet
    default: true
---

# Nebula Catalog


<div align="center">
  <img src="banner.jpg" alt="The Crab Nebula observed by the Hubble Space Telescope" width="400">
  <p><em>Credit: NASA/ESA/Hubble</em></p>
</div>


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

## Dataset description

Catalog of nebulae sourced from Wikidata, covering emission, reflection, dark, and planetary nebulae across the sky.

Nebulae are clouds of interstellar gas and dust -- the birthplaces of stars, the remnants of dying ones, and some of the most visually spectacular objects in the universe. This dataset aggregates structured data from Wikidata's knowledge base, drawing on decades of cataloguing from Messier, NGC, IC, and other surveys.

Each entry includes the nebula's name, type, host constellation, equatorial coordinates (right ascension and declination), and representative catalog identifiers. This enables sky-survey cross-matching, population studies by type or constellation, and spatial distribution analysis.

Sourced from Wikidata SPARQL using P31 (instance of) for emission (Q207326), reflection (Q167278), dark (Q46587), and planetary (Q204194) nebulae.


This dataset is suitable for **tabular classification** tasks.

## Schema

| Column | Type | Description | Sample | Null % |
|--------|------|-------------|--------|--------|
| `wikidata_id` | string | Wikidata entity ID (e.g. 'Q12345'); stable URI for cross-referencing other catalogs and knowledge bases | Q85589522 | 0.0% |
| `name` | string | Common or catalog name as recorded in Wikidata (e.g. 'Orion Nebula', 'NGC 1499', 'Barnard 68'); null for objects with no recorded label | 2dFS 1734 | 0.0% |
| `nebula_type` | string | Physical nebula class: 'planetary nebula' (expanding shell from AGB star), 'emission nebula' (ionized HII region), 'reflection nebula' (dust scattering starlight), 'dark nebula' (opaque dust blocking background), 'supernova remnant' (ejecta from stellar explosion) | dark nebula | 0.0% |
| `constellation` | string | IAU constellation in which the nebula is located (e.g. 'Orion', 'Cygnus'); null if not recorded in Wikidata | Tucana | 2.0% |
| `ra_deg` | float64 | Right ascension in decimal degrees, ICRS J2000.0; range 0-360; null if coordinates not in Wikidata | 15.773833 | 0.8% |
| `dec_deg` | float64 | Declination in decimal degrees, ICRS J2000.0; range -90 to +90; null if coordinates not in Wikidata | -72.167944 | 0.8% |
| `catalog_id` | string | Cross-reference identifiers from NGC, IC, Messier, and other catalogs, semicolon-separated (e.g. 'NGC 1952; M 1'); null for objects catalogued only in Wikidata | 2dFS 1734; MCPS 1.051561-72.16803; OG... | 0.1% |

## Quick stats

- **21,033** nebulae total
- **20,864** with equatorial coordinates
- **21,018** with catalog identifiers
- Top constellations: Aquila (2,352), Scutum (1,750), Scorpius (1,656), Sagittarius (1,648), Cygnus (1,409)

### Breakdown by type

- **dark nebula**: 21,031
- **emission nebula**: 1
- **reflection nebula**: 1

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/nebula-catalog", split="train")
df = ds.to_pandas()
```

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/nebula-catalog", split="train")
df = ds.to_pandas()

# Count by nebula type
print(df["nebula_type"].value_counts())

# Planetary nebulae with coordinates
pn = df[(df["nebula_type"] == "planetary nebula") & df["ra_deg"].notna()]
print(pn[["name", "constellation", "ra_deg", "dec_deg"]].head(10))

# Nebulae in Orion
orion = df[df["constellation"] == "Orion"]
print(f"{len(orion):,} nebulae in Orion")

# Distribution by type
import matplotlib.pyplot as plt
df["nebula_type"].value_counts().plot.barh()
plt.xlabel("Count")
plt.title("Nebulae by Type")
plt.tight_layout()
plt.show()
```

## Data source

https://www.wikidata.org/

## Related datasets

- [juliensimon/planetary-nebulae](https://huggingface.co/datasets/juliensimon/planetary-nebulae)

- [juliensimon/ngc-ic-catalog](https://huggingface.co/datasets/juliensimon/ngc-ic-catalog)

- [juliensimon/messier-catalog](https://huggingface.co/datasets/juliensimon/messier-catalog)

> If you find this dataset useful, please consider [giving it a like](https://huggingface.co/datasets/juliensimon/nebula-catalog) on Hugging Face. It helps others discover it.

## About the author

Created by [Julien Simon](https://julien.org) — AI Operating Partner at Fortino Capital. Part of the [Space Datasets](https://julien.org/datasets) collection.

## Citation

```bibtex
@dataset{nebula_catalog,
  title = {Nebula Catalog},
  author = {juliensimon},
  year = {2026},
  url = {https://huggingface.co/datasets/juliensimon/nebula-catalog},
  publisher = {Hugging Face}
}
```

## License

[CC0-1.0](https://creativecommons.org/licenses/by/4.0/)