---
id: pyvo
version: "1.9.1"
license: BSD-3-Clause
license_treatment: permissive
maintenance: active
---

# pyvo — Astropy affiliated package for accessing Virtual Observatory data and services

License: permissive · Maintenance: active · Downloads: 442.0K/mo

## What it is and what it does

PyVO is an Astropy-affiliated package that bridges Python and the Virtual Observatory ecosystem, a standardized infrastructure for sharing astronomical data and services across institutions. It abstracts away the complexity of VO protocols (like cone search, SIA, and TAP) so astronomers and developers can query remote archives, catalogs, and analysis tools as if they were local Python objects.

The package sits between your Python code and thousands of distributed VO-compliant resources worldwide. Instead of learning multiple archive APIs, you use PyVO's unified interface to discover and retrieve data—spectroscopy, images, catalogs, time series—from any participating observatory or data center. It integrates tightly with astropy and numpy, so results come back as familiar data structures ready for analysis.

Use it for:

- Query multiple sky surveys for objects in a region without learning each archive's API separately.
- Build automated pipelines that fetch spectroscopic or photometric data from remote VO services.
- Prototype new VO-based analysis tools before they become formal standards.
- Combine data from distributed archives in a single Python workflow.
- Access specialized databases (time series, variable stars, exoplanet catalogs) through a uniform interface.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

PyVO provides Python access to Virtual Observatory data archives, catalogs, and web services using standardized VO protocols, leveraging astropy and requests to query thousands of remote astronomical resources.

Yes. PyVO is actively maintained, has low install friction, carries a permissive license, and fills a real gap for astronomers needing programmatic access to distributed VO resources. It is the standard Python tool for this task and backed by the Astropy project. No security vulnerabilities reported.

## Install

pip install pyvo
uv add pyvo
poetry add pyvo

## Installing pyvo

Before you install: Low install friction; pure Python wheel with only astropy and requests as runtime dependencies. Actively maintained with recent commits and releases since 2013, supporting current Python versions (3.10+).

License in practice: BSD-3-Clause permissive license allows commercial and private use with minimal restrictions; suitable for most projects.

Quickstart:

pip install pyvo

import pyvo as vo
# Query a VO service
result = vo.conesearch(ra=0, dec=0, radius=0.1)

Requires Python 3.10 or later; network access needed for most queries.

Verify before relying:

- Specific number of accessible catalogs and archives claimed in description ('thousands') not independently verified in fact sheet.
- Performance characteristics for large result sets or concurrent queries not documented in fact sheet.

## Package facts

- License: BSD-3-Clause (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 442.0K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

virtual observatory data access, astronomical catalog queries, VO standards python, remote astronomy archives, astropy vo services, sky survey data retrieval, vo protocol client, astronomy, virtual-observatory, astropy-affiliated

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