juliensimon/bright-star-catalog

---
license: cc-by-4.0
pretty_name: "Bright Star Catalogue (BSC5)"
language:
- en
description: >-
Bright Star Catalogue (BSC5, 5th Revised Edition) — 9,110 naked-eye stars
(magnitude <= 6.5) with UBVRI photometry, MK spectral types, proper motions,
parallax, radial and rotational velocities, and multiplicity information.
Sourced via VizieR V/50.
size_categories:
- 1K<n<10K
task_categories:
- tabular-classification
- tabular-regression
tags:
- space
- stars
- bright-stars
- stellar
- naked-eye
- bsc5
- yale
- astronomy
- open-data
- tabular-data
- parquet
configs:
- config_name: default
data_files:
- split: train
path: data/bright_stars.parquet
default: true
---

# Bright Star Catalogue (BSC5)

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

The Bright Star Catalogue (BSC5, 5th Revised Edition) containing **9,110** naked-eye stars
brighter than visual magnitude ~6.5 with UBVRI photometry, MK spectral types, proper motions,
radial and rotational velocities, and multiplicity information.

## Dataset description

The Bright Star Catalogue (Hoffleit & Warren, 1991) is THE standard reference for naked-eye
stars. Originally compiled at Yale University Observatory, the 5th Revised Edition contains
9,110 entries covering every star visible to the unaided eye from the entire sky. It includes
Harvard Revised (HR) photometry numbers, Henry Draper (HD) numbers, UBVRI broadband photometry,
MK spectral classification, proper motions, trigonometric parallaxes, radial velocities,
rotational velocities (v sin i), and flags for variability and multiplicity.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `hr_number` | int64 | Harvard Revised (HR) photometry number (primary key) |
| `name` | string | Common star name (if any) |
| `hd_number` | int64 | Henry Draper catalog number |
| `ra_deg` | float64 | Right ascension (degrees, J2000) |
| `dec_deg` | float64 | Declination (degrees, J2000) |
| `v_mag` | float64 | Visual (V) magnitude |
| `b_v_color` | float64 | B-V color index |
| `u_b_color` | float64 | U-B color index |
| `r_i_color` | float64 | R-I color index |
| `spectral_type` | string | MK spectral classification |
| `spectral_class` | string | Spectral class letter (O, B, A, F, G, K, M) |
| `pm_ra_arcsec_yr` | float64 | Proper motion in RA (arcsec/yr) |
| `pm_dec_arcsec_yr` | float64 | Proper motion in Dec (arcsec/yr) |
| `radial_velocity_kms` | float64 | Radial velocity (km/s) |
| `rotational_velocity_kms` | float64 | Rotational velocity v sin i (km/s) |
| `parallax_mas` | float64 | Trigonometric parallax (milliarcseconds) |
| `variable_name` | string | Variable star designation |
| `is_variable` | bool | True if star is a known variable |
| `multiplicity_flag` | string | Multiplicity catalog codes |
| `is_multiple` | bool | True if star is in a multiple system |

## Quick stats

- **9,110** stars total
- Brightest: **-1.46** mag / Faintest: **7.96** mag
- **2,182** variable stars, **0** multiple systems

### By spectral class

- **O**: 51
- **B**: 1,757
- **A**: 1,963
- **F**: 1,287
- **G**: 1,145
- **K**: 2,065
- **M**: 506

## Usage

```python
from datasets import load_dataset

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

# Brightest stars
bright = df.nsmallest(20, "v_mag")
print(bright[["hr_number", "name", "v_mag", "spectral_type"]])

# Color-magnitude diagram
import matplotlib.pyplot as plt
valid = df.dropna(subset=["b_v_color", "v_mag"])
plt.scatter(valid["b_v_color"], valid["v_mag"], s=1, alpha=0.5)
plt.gca().invert_yaxis()
plt.xlabel("B-V Color Index")
plt.ylabel("V Magnitude")
plt.title("Bright Star Catalogue: Color-Magnitude Diagram")

# Spectral class distribution
df["spectral_class"].value_counts().sort_index().plot(kind="bar")
plt.title("Stars by Spectral Class")
```

## Data source

Hoffleit, D. & Warren, W.H. Jr. (1991), "The Bright Star Catalogue, 5th Revised Ed.",
Yale University Observatory. Accessed via
[VizieR V/50](https://vizier.cds.unistra.fr/viz-bin/VizieR-3?-source=V/50/catalog),
CDS Strasbourg.

## Related datasets

- [wolf-rayet-stars](https://huggingface.co/datasets/juliensimon/wolf-rayet-stars) -- Wolf-Rayet Star Catalogue
- [brown-dwarf-catalog](https://huggingface.co/datasets/juliensimon/brown-dwarf-catalog) -- Brown Dwarf Catalog
- [hipparcos-catalog](https://huggingface.co/datasets/juliensimon/hipparcos-catalog) -- Hipparcos Star 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/bright-star-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{bright_star_catalog,
author = {Simon, Julien},
title = {Bright Star Catalogue (BSC5)},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/bright-star-catalog},
note = {Based on Bright Star Catalogue 5th Rev. Ed. (Hoffleit & Warren 1991) via VizieR V/50}
}
```

## License

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