juliensimon/ngc-ic-catalog

---
license: cc-by-sa-4.0
pretty_name: "NGC/IC Deep-Sky Object Catalog"
language:
- en
description: "Complete NGC and IC deep-sky object catalog from OpenNGC — galaxies, nebulae, and star clusters. Updated monthly."
task_categories:
- tabular-classification
tags:
- ngc
- ic
- deep-sky
- nebula
- galaxy
- star-cluster
- astronomy
- open-data
- messier
size_categories:
- 10K<n<100K
---

# NGC/IC Deep-Sky Object Catalog


Complete catalog of **13,969** deep-sky objects from the
[OpenNGC](https://github.com/mattiaverga/OpenNGC) project, covering every NGC and IC
entry — galaxies, nebulae, star clusters, and more.

## Dataset description

The New General Catalogue (NGC) and Index Catalogue (IC) are the standard references for
deep-sky objects beyond the Messier catalog. This dataset is built from the community-maintained
OpenNGC database, which provides accurate positions, magnitudes, dimensions, and classifications
for all NGC/IC entries.

## Quick stats

- **13,969** cataloged objects
- **10,749** galaxies, **433** nebulae, **918** star clusters, **1,869** other
- **107** Messier objects cross-referenced
- **89** constellations represented

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `name` | string | Object designation (e.g. "NGC0001", "IC1234") |
| `type` | string | Morphological type code (G, OCl, PN, EmN, etc.) |
| `object_category` | string | Broad category: Galaxy, Nebula, Star Cluster, Other |
| `ra` | string | Right ascension (J2000) |
| `dec` | string | Declination (J2000) |
| `const` | string | Constellation abbreviation |
| `majax` | float | Major axis (arcmin) |
| `minax` | float | Minor axis (arcmin) |
| `posang` | float | Position angle (degrees) |
| `b_mag` | float | B-band magnitude |
| `v_mag` | float | V-band (visual) magnitude |
| `j_mag` | float | J-band magnitude |
| `h_mag` | float | H-band magnitude |
| `k_mag` | float | K-band magnitude |
| `surfbr` | float | Surface brightness |
| `hubble` | string | Hubble morphological type (galaxies) |
| `m` | string | Messier number, if applicable |
| `ngc` | string | Cross-referenced NGC number |
| `ic` | string | Cross-referenced IC number |
| `common_names` | string | Common names (e.g. "Andromeda Galaxy") |
| `identifiers` | string | Other catalog identifiers |

## Usage

```python
from datasets import load_dataset

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

# All galaxies
galaxies = df[df["object_category"] == "Galaxy"]
print(f"{len(galaxies):,} galaxies")

# Messier objects
messier = df[df["m"].notna()]
print(f"{len(messier)} Messier objects")

# Brightest objects by V-mag
brightest = df.dropna(subset=["v_mag"]).nsmallest(20, "v_mag")

# Objects per constellation
by_const = df["const"].value_counts().head(10)
```

## Data source

All data comes from the [OpenNGC](https://github.com/mattiaverga/OpenNGC) project,
a community-maintained database of NGC/IC objects licensed under CC-BY-SA-4.0.

## Update schedule

Monthly (1st Monday at 18:30 UTC) via [GitHub Actions](https://github.com/juliensimon/space-datasets).

## Related datasets

- [space-track-satcat](https://huggingface.co/datasets/juliensimon/space-track-satcat) — NORAD Satellite Catalog
- [space-launch-log](https://huggingface.co/datasets/juliensimon/space-launch-log) — Global launch history from GCAT
- [starlink-fleet-data](https://huggingface.co/datasets/juliensimon/starlink-fleet-data) — Daily Starlink constellation health

## Pipeline

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

## Citation

```bibtex
@dataset{ngc_ic_catalog,
author = {Simon, Julien},
title = {NGC/IC Deep-Sky Object Catalog},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/ngc-ic-catalog},
note = {Based on OpenNGC (Mattia Verga) — CC-BY-SA-4.0}
}
```

## License

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