juliensimon/quasar-catalog

---
license: cc-by-4.0
pretty_name: "Quasar & AGN Catalog"
language:
- en
description: >-
Catalog of 50,000 quasars and active galactic nuclei from SIMBAD — quasars,
Seyfert galaxies, blazars, and LINERs with redshifts and photometry.
size_categories:
- 10K<n<100K
task_categories:
- tabular-classification
- tabular-regression
tags:
- open-data
- astronomy
- quasar
- agn
- blazar
- seyfert
- redshift
- simbad
- cosmology
configs:
- config_name: default
data_files:
- split: train
path: data/quasars.parquet
---

# Quasar & AGN Catalog


Catalog of **50,000** quasars and active galactic nuclei from
[SIMBAD](https://simbad.u-strasbg.fr/): **11,784** quasars, **19,665**
Seyfert galaxies, **2,482** blazars/BL Lacs, **7,377** general AGN.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `name` | string | Primary SIMBAD identifier |
| `ra_deg` | float | Right ascension (degrees) |
| `dec_deg` | float | Declination (degrees) |
| `object_type` | string | SIMBAD type code (QSO, AGN, Sy1, Sy2, BLL, Bla, LIN) |
| `agn_category` | string | Readable category (Quasar, Seyfert 1, Blazar, etc.) |

## Quick stats

- **50,000** objects
- **11,784** quasars, **19,665** Seyferts, **2,482** blazars

## Usage

```python
from datasets import load_dataset

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

# AGN type breakdown
df["agn_category"].value_counts()
```

## Update frequency

Updated **weekly on Monday at 19:00 UTC** via GitHub Actions.

## Data source

[SIMBAD Astronomical Database](https://simbad.u-strasbg.fr/) (CDS, Strasbourg).

## Related datasets

- [black-hole-catalog](https://huggingface.co/datasets/juliensimon/black-hole-catalog) — Known black hole systems and X-ray binaries
- [messier-catalog](https://huggingface.co/datasets/juliensimon/messier-catalog) — 110 iconic deep-sky objects
- [ngc-ic-catalog](https://huggingface.co/datasets/juliensimon/ngc-ic-catalog) — 14K deep-sky objects (NGC + IC)
- [galaxy-clusters](https://huggingface.co/datasets/juliensimon/galaxy-clusters) — 1,650+ Planck SZ-detected clusters

## Pipeline

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

## Citation

```bibtex
@dataset{quasar_catalog,
author = {Simon, Julien},
title = {Quasar & AGN Catalog},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/quasar-catalog},
note = {Based on SIMBAD astronomical database (CDS Strasbourg)}
}
```