Update nebula catalog: 60,363 nebulae

README.md

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+---
+license: cc0-1.0
+pretty_name: "Nebula Catalog"
+language:
+  - en
+description: >-
+  Catalog of nebulae sourced from Wikidata, covering emission, reflection,
+  dark, and planetary nebulae. 60,363 entries with coordinates, distances,
+  angular sizes, and constellation assignments.
+size_categories:
+  - 10K<n<100K
+task_categories:
+  - tabular-classification
+tags:
+  - space
+  - astronomy
+  - nebulae
+  - deep-sky
+  - wikidata
+  - open-data
+  - tabular-data
+  - parquet
+configs:
+  - config_name: default
+    default: true
+    data_files:
+      - split: train
+        path: data/nebulae.parquet
+---
+
+# Nebula Catalog
+
+*Part of the [Astronomy Datasets](https://huggingface.co/collections/juliensimon/astronomy-datasets-69c24caf2f17e36128946743) collection on Hugging Face.*
+
+A comprehensive catalog of **60,363** nebulae sourced from [Wikidata](https://www.wikidata.org/),
+covering emission, reflection, dark, and planetary nebulae across the sky.
+
+## Dataset description
+
+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), distance from Earth, angular
+size on the sky, and a representative catalog identifier. This enables
+sky-survey cross-matching, population studies by type or constellation, and
+distance/size distribution analysis.
+
+Sourced from Wikidata SPARQL using P31 (instance of) for emission (Q207326),
+reflection (Q167278), dark (Q46587), and planetary (Q204194) nebulae.
+
+## Schema
+
+| Column | Type | Description |
+|--------|------|-------------|
+| `wikidata_id` | string | Wikidata entity ID (e.g. Q12345) |
+| `name` | string | Common or catalog name |
+| `nebula_type` | string | Nebula type (emission, reflection, dark, planetary) |
+| `constellation` | string | Host constellation |
+| `ra_deg` | float | Right ascension (degrees) |
+| `dec_deg` | float | Declination (degrees) |
+| `distance_ly` | float | Distance from Earth (light-years) |
+| `angular_size` | float | Angular size (arcminutes) |
+| `catalog_id` | string | Catalog identifier (NGC, IC, Messier, etc.) |
+
+## Quick stats
+
+- **60,363** nebulae total
+- **38,616** with equatorial coordinates
+- **294** with distance measurements
+- Distance range: 3 – 67,200,000 light-years
+- Top constellations: Boötes (2,663), Aquila (2,363), Scutum (1,751), Sagittarius (1,688), Scorpius (1,667)
+
+### Breakdown by type
+
+- **dark nebula**: 21,031
+- **active galactic nucleus**: 17,587
+- **summit**: 17,275
+- **hill**: 2,695
+- **mountain**: 1,539
+- **spiral galaxy**: 129
+- **volcano**: 16
+- **star**: 13
+
+## Usage
+
+```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 known distances
+pn = df[(df["nebula_type"] == "planetary nebula") & df["distance_ly"].notna()]
+print(pn[["name", "constellation", "distance_ly"]].sort_values("distance_ly").head(10))
+
+# Nebulae in Orion
+orion = df[df["constellation"] == "Orion"]
+print(f"{len(orion):,} nebulae in Orion")
+
+# Largest nebulae by angular size
+largest = df[df["angular_size"].notna()].nlargest(10, "angular_size")
+print(largest[["name", "nebula_type", "angular_size", "constellation"]])
+```
+
+## Data source
+
+[Wikidata](https://www.wikidata.org/) SPARQL endpoint. Nebulae identified via
+property P31 (instance of) for four nebula-type entities. Data is
+community-curated and reflects contributions from astronomical cataloguing
+projects worldwide.
+
+## Update schedule
+
+Quarterly (January, April, July, October). Re-run manually at any time to
+pick up newly catalogued objects.
+
+## Related datasets
+
+- [planetary-nebulae](https://huggingface.co/datasets/juliensimon/planetary-nebulae) -- dedicated planetary nebula catalog
+- [ngc-ic-catalog](https://huggingface.co/datasets/juliensimon/ngc-ic-catalog) -- NGC/IC catalog of deep-sky objects
+- [messier-catalog](https://huggingface.co/datasets/juliensimon/messier-catalog) -- Messier catalog
+
+## Pipeline
+
+Source code: [juliensimon/space-datasets](https://github.com/juliensimon/space-datasets)
+
+## Support
+
+If you find this dataset useful, please give it a ❤️ on the [dataset page](https://huggingface.co/datasets/juliensimon/nebula-catalog) and share feedback in the Community tab! Also consider giving a ⭐️ to the [space-datasets](https://github.com/juliensimon/space-datasets) repo.
+
+## Citation
+
+```bibtex
+@dataset{nebula_catalog,
+  author = {Simon, Julien},
+  title = {Nebula Catalog},
+  year = {2026},
+  publisher = {Hugging Face},
+  url = {https://huggingface.co/datasets/juliensimon/nebula-catalog},
+  note = {Sourced from Wikidata (CC0)}
+}
+```
+
+## License
+
+[CC0-1.0](https://creativecommons.org/publicdomain/zero/1.0/) (Wikidata content is public domain)

data/nebulae.parquet

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