---
license: cc-by-4.0
pretty_name: "Ritter & Kolb Cataclysmic Variable Catalog"
language:
  - en
description: "Catalog of cataclysmic variables (CVs) from the Ritter & Kolb catalog — white dwarfs accreting from companion stars"
task_categories:
  - tabular-classification
tags:
  - space
  - cataclysmic-variable
  - white-dwarf
  - nova
  - dwarf-nova
  - binary-star
  - astronomy
  - accretion
  - open-data
  - tabular-data
  - parquet
size_categories:
  - 1K<n<10K
configs:
  - config_name: default
    data_files:
      - split: train
        path: data/cataclysmic_variables.parquet
    default: true
---

# Ritter & Kolb Cataclysmic Variable Catalog

<div align="center">
  <img src="banner.jpg" alt="The Crab Nebula, a supernova remnant" width="400">
  <p><em>Credit: NASA/ESA/Hubble</em></p>
</div>

*Part of the [Astronomy Datasets](https://huggingface.co/collections/juliensimon/astronomy-datasets-69c24caf2f17e36128946743) and [Variable Stars & Transients](https://huggingface.co/collections/juliensimon/variable-stars-transients-69c24caf2f17e36128946744) collections on Hugging Face.*

![Update Cataclysmic Variables](https://github.com/juliensimon/space-datasets/actions/workflows/update-cataclysmic-variables.yml/badge.svg)
![Updated](https://img.shields.io/badge/dynamic/json?url=https://raw.githubusercontent.com/juliensimon/space-datasets/main/status.json&query=$.cataclysmic-variables&label=updated&color=brightgreen)

The Ritter & Kolb catalog of cataclysmic variables (CVs), sourced from NASA HEASARC.
Currently **1,168** CVs with 51 attributes.

## Dataset description

Cataclysmic variables (CVs) are binary star systems in which a white dwarf accretes
matter from a low-mass companion star (typically a red dwarf) that overflows its Roche
lobe. The infalling material forms an accretion disk around the white dwarf, producing
dramatic brightness variations across timescales from seconds to decades. CVs are
classified into several subtypes based on their outburst behavior and magnetic field
strength:

- **Dwarf novae** (DN): exhibit quasi-periodic outbursts of 2-8 magnitudes caused by
  thermal instabilities in the accretion disk. Includes SU UMa, U Gem, and Z Cam subtypes.
- **Classical novae** (N): undergo thermonuclear explosions on the white dwarf surface
  when accreted hydrogen reaches a critical mass, brightening by 6-19 magnitudes.
- **Polars** (AM Her): strongly magnetic white dwarfs (B ~ 10-230 MG) where the magnetic
  field channels accretion directly onto the poles, preventing disk formation.
- **Intermediate polars** (DQ Her): moderately magnetic white dwarfs (B ~ 1-10 MG)
  with a truncated accretion disk and magnetically channeled inner flow.
- **Nova-like variables** (NL): high mass-transfer rate systems in a persistent
  bright state without the outburst cycles of dwarf novae.

The Ritter & Kolb catalog is the standard reference catalog for CV research, containing
orbital periods, spectral types, magnitudes, and classifications for the known CV
population. This dataset is essential for population studies, period distribution
analysis, and understanding the evolution of compact binary systems.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `__row` | str |  |
| `name` | str | Primary designation of the cataclysmic variable |
| `alt_name` | str |  |
| `ra` | float64 | Right ascension (J2000) in degrees |
| `dec` | float64 | Declination (J2000) in degrees |
| `lii` | float64 | Galactic longitude in degrees |
| `bii` | float64 | Galactic latitude in degrees |
| `acc_pos` | str |  |
| `type1` | str |  |
| `type1_flag` | str |  |
| `type2` | str | Secondary type classification |
| `type2_flag` | str |  |
| `type3` | str |  |
| `type3_flag` | str |  |
| `type4` | str |  |
| `type4_flag` | str |  |
| `mag1` | float64 | Primary magnitude (typically in V band) |
| `mag2` | float64 | Secondary magnitude (typically at minimum brightness) |
| `mag3` | float64 |  |
| `mag4` | float64 |  |
| `interval` | str |  |
| `interval2` | str |  |
| `orbital_period` | float64 |  |
| `period2` | float64 |  |
| `period3` | float64 |  |
| `period4` | float64 |  |
| `eclipse` | str |  |
| `sb` | str |  |
| `spect_type_2` | str |  |
| `spect_type_1` | str |  |
| `lim_mass_ratio` | str |  |
| `mass_ratio` | str |  |
| `mass_ratio_flag` | str |  |
| `mass_ratio_error` | str |  |
| `lim_inclination` | str |  |
| `inclination` | str |  |
| `inclination_flag` | str |  |
| `inclination_error` | str |  |
| `lim_m1` | str |  |
| `m1` | str |  |
| `m1_flag` | str |  |
| `m1_error` | str |  |
| `lim_m2` | str |  |
| `m2` | str |  |
| `m2_flag` | str |  |
| `m2_error` | str |  |
| `class` | str | Object classification code from Ritter & Kolb |
| `__x_ra_dec` | str |  |
| `__y_ra_dec` | str |  |
| `__z_ra_dec` | str |  |
| `cv_subtype` | str | Derived CV subtype: dwarf_nova, polar, intermediate_polar, nova_like, classical_nova, or other |

## Quick stats

- **1,168** cataclysmic variables
- **0** systems with measured orbital period
- CV subtypes:
  - **other**: 1,166

## Usage

```python
from datasets import load_dataset

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

# Filter by CV subtype
dwarf_novae = df[df['cv_subtype'] == 'dwarf_nova']
polars = df[df['cv_subtype'] == 'polar']

# Period distribution
# No period column available

# Sky distribution
import matplotlib.pyplot as plt
import numpy as np
fig, ax = plt.subplots(subplot_kw={"projection": "aitoff"})
ra = np.radians(df["ra"].values - 180) if "ra" in df.columns else []
dec = np.radians(df["dec"].values) if "dec" in df.columns else []
ax.scatter(ra, dec, s=1, alpha=0.5)
plt.title("Cataclysmic Variables - Sky Distribution")
```

## Data source

All data comes from the [Ritter & Kolb Cataclysmic Binaries catalog](https://heasarc.gsfc.nasa.gov/W3Browse/all/rittercv.html)
hosted by NASA's High Energy Astrophysics Science Archive Research Center (HEASARC),
accessed via the TAP protocol. Originally published in:
Ritter H., Kolb U., 2003, A&A 404, 301 (Edition 7.24).

## Update schedule

Quarterly (Feb/May/Aug/Nov 1st at 08:30 UTC) via [GitHub Actions](https://github.com/juliensimon/space-datasets).

## Related datasets

- [xray-binary-catalog](https://huggingface.co/datasets/juliensimon/xray-binary-catalog) — X-ray binary systems
- [gaia-dr3-white-dwarfs](https://huggingface.co/datasets/juliensimon/gaia-dr3-white-dwarfs) — Gaia white dwarf catalog
- [gcvs-variable-stars](https://huggingface.co/datasets/juliensimon/gcvs-variable-stars) — General Catalogue of Variable Stars
- [kepler-eclipsing-binaries](https://huggingface.co/datasets/juliensimon/kepler-eclipsing-binaries) — Kepler eclipsing binary catalog

## Pipeline

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

## Support

If you find this dataset useful, please give it a heart on the [dataset page](https://huggingface.co/datasets/juliensimon/cataclysmic-variable-catalog) and share feedback in the Community tab! Also consider giving a star to the [space-datasets](https://github.com/juliensimon/space-datasets) repo.

## Citation

```bibtex
@dataset{cataclysmic_variable_catalog,
  author = {Simon, Julien},
  title = {Ritter & Kolb Cataclysmic Variable Catalog},
  year = {2026},
  publisher = {Hugging Face},
  url = {https://huggingface.co/datasets/juliensimon/cataclysmic-variable-catalog},
  note = {Based on Ritter & Kolb (2003) catalog, sourced from NASA HEASARC}
}
```

## License

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