---
license: cc-by-4.0
pretty_name: "FUSE Observation Catalog"
language:
  - en
description: "The FUSE Observation Catalog indexes every observation obtained by NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), which operated from June 24, 1999 to October 18, 2007. FUSE was uniquely design"
task_categories:
  - tabular-classification
tags:
  - space
  - fuse
  - nasa
  - ultraviolet
  - far-uv
  - spectroscopy
  - astronomy
  - telescope
  - open-data
  - tabular-data
  - parquet
size_categories:
  - 1K<n<10K
configs:
  - config_name: default
    data_files:
      - split: train
        path: data/fuse_observations.parquet
    default: true
---

# FUSE Observation Catalog


<div align="center">
  <img src="banner.jpg" alt="Representative view of the UV sky — FUSE covered the 905–1187 Å band uniquely" width="400">
  <p><em>Credit: NASA/GSFC</em></p>
</div>


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

## Dataset description

The FUSE Observation Catalog indexes every observation obtained by NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), which operated from June 24, 1999 to October 18, 2007. FUSE was uniquely designed to observe the hard-to-reach far-UV band between 905 and 1187 Å, where critical absorption lines from H₂, O VI, and deuterium fall — wavelengths inaccessible to Hubble's instruments. Its four coaligned Rowland-circle spectrographs delivered resolving power R ≈ 20,000, the highest ever achieved in space at these wavelengths.

Each row is one FUSE pointing. The archive totals roughly 5,700 observations — modest in count but extraordinarily high-value because of the unique wavelength coverage. FUSE targets include hot white dwarfs (temperature probes via Lyman series), the diffuse interstellar medium (mapping H₂ and O VI in the Milky Way halo), extragalactic quasars (probing the intergalactic medium via absorption), and early-type stars (stellar winds and mass-loss rates).

This dataset is designed for cross-matching with other UV catalogs (IUE, HST, GALEX), identifying FUSE coverage of any sightline of interest, and as a lookup table for retrieving individual spectra from MAST. It complements the HST, IUE, GALEX, JWST, and Chandra observation catalogs in this collection — FUSE fills the 905–1187 Å band that no other mission in that set covers.

The catalog is derived from MAST's CAOM table `dbo.caomobservation` (collection = 'FUSE'). The archive is static since 2007, so this dataset refreshes quarterly for any late reprocessing or metadata fixes.

This dataset is suitable for **tabular classification** tasks.

## Schema

| Column | Type | Description | Sample | Null % |
|--------|------|-------------|--------|--------|
| `obs_id` | string | FUSE observation identifier (11-char alphanumeric, e.g., 'a0010101000'). Primary key. | a0010101000 | 0.0% |
| `obstype` | string | CAOM observation type: 'S' (simple) or 'C' (composite) | S | 0.0% |
| `intent` | string | Observation intent: 'science' or 'calibration' | science | 0.0% |
| `proposal_id` | string | FUSE proposal identifier (e.g., 'A001', 'B234'); cycle-letter + sequence | A001 | 11.7% |
| `proposal_pi` | string | Principal Investigator name (free-form) | Werner | 11.7% |
| `target_name` | string | Target name as provided by the proposer | HE0504-2408 | 0.0% |
| `target_ra` | float64 | Target right ascension in decimal degrees (ICRS) | 76.57566700000001 | 0.0% |
| `target_dec` | float64 | Target declination in decimal degrees (ICRS) | -24.067194 | 0.0% |

## Quick stats

- **5,729** FUSE far-UV spectra (1999–2007)
- **2,807** distinct target names
- **238** distinct Principal Investigators
- Unique wavelength coverage: **905–1187 Å** (H₂, O VI, deuterium lines)

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/fuse-observations", split="train")
df = ds.to_pandas()
```

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/fuse-observations", split="train")
df = ds.to_pandas()

# Top-observed targets
top = df["target_name"].value_counts().head(20)
print(top)

# Sky distribution
import matplotlib.pyplot as plt
plt.figure(figsize=(12, 6))
plt.scatter(df["target_ra"], df["target_dec"], s=1, alpha=0.5)
plt.xlabel("RA (deg)"); plt.ylabel("Dec (deg)")
plt.gca().invert_xaxis()
plt.title("FUSE target pointings (1999–2007)")
plt.show()
```

## Data source

https://archive.stsci.edu/missions-and-data/fuse

## Update schedule

Quarterly (1st of Jan/Apr/Jul/Oct at 16:00 UTC) via [GitHub Actions](https://github.com/juliensimon/space-datasets).

## Related datasets

- [juliensimon/iue-observations](https://huggingface.co/datasets/juliensimon/iue-observations)

- [juliensimon/hst-observations](https://huggingface.co/datasets/juliensimon/hst-observations)

- [juliensimon/galex-observations](https://huggingface.co/datasets/juliensimon/galex-observations)

- [juliensimon/euve-observations](https://huggingface.co/datasets/juliensimon/euve-observations)

- [juliensimon/quasar-catalog](https://huggingface.co/datasets/juliensimon/quasar-catalog)

> If you find this dataset useful, please consider [giving it a like](https://huggingface.co/datasets/juliensimon/fuse-observations) on Hugging Face. It helps others discover it.

## About the author

Created by [Julien Simon](https://julien.org) — AI Operating Partner at Fortino Capital. Part of the [Space Datasets](https://julien.org/datasets) collection.

## Citation

```bibtex
@dataset{fuse_observations,
  title = {FUSE Observation Catalog},
  author = {Simon, Julien},
  year = {2026},
  url = {https://huggingface.co/datasets/juliensimon/fuse-observations},
  publisher = {Hugging Face},
  note = {Derived from MAST, Space Telescope Science Institute, https://archive.stsci.edu/missions-and-data/fuse}
}
```
## License

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