Astropy

If you're working with astronomical data in Python, this is the standard library you reach for. It handles the everyday astronomy tasks: transforming between coordinate systems (ICRS to Galactic to AltAz), converting units with proper dimensional analysis, reading and writing FITS files, and doing cosmological calculations with models like Planck18. The time handling is precise enough for professional astronomy work, supporting different time scales and formats. It also includes table operations for catalog work and WCS transformations for mapping between pixel and sky coordinates. Honestly, it's comprehensive enough that you'll spend time learning which submodule does what, but that beats reinventing coordinate math or FITS parsers yourself.

skills.sh installs: 312
GitHub stars: 33.2K
last updated: Aug 21, 2026

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Install

$ npx -y skills add davila7/claude-code-templates --skill astropy --agent claude-code

Installs into .claude/skills of the current project.

Files

Astropy

Overview

Astropy is the core Python package for astronomy, providing essential functionality for astronomical research and data analysis. Use astropy for coordinate transformations, unit and quantity calculations, FITS file operations, cosmological calculations, precise time handling, tabular data manipulation, and astronomical image processing.

When to Use This Skill

Use astropy when tasks involve:

Converting between celestial coordinate systems (ICRS, Galactic, FK5, AltAz, etc.)
Working with physical units and quantities (converting Jy to mJy, parsecs to km, etc.)
Reading, writing, or manipulating FITS files (images or tables)
Cosmological calculations (luminosity distance, lookback time, Hubble parameter)
Precise time handling with different time scales (UTC, TAI, TT, TDB) and formats (JD, MJD, ISO)
Table operations (reading catalogs, cross-matching, filtering, joining)
WCS transformations between pixel and world coordinates
Astronomical constants and calculations