What does it do?
Astropy handles the unglamorous but essential plumbing of astronomy research: converting between different ways of measuring time and celestial coordinates, reading the specialized FITS file format telescopes save images in, and doing unit conversions between things like light-years and parsecs without error. It’s the standardized measuring tape and universal translator every astronomer agrees to use, so data from a telescope in Chile and one in Hawaii can be compared apples to apples. Before Astropy, individual observatories and researchers often maintained their own separate, incompatible tools for these exact same basic tasks. It’s specifically built as shared community infrastructure rather than one lab’s private toolkit.
See it in action
This opens a telescope’s saved image data file, and separately shows how to convert an astronomical distance measurement from one unit into another.
from astropy.io import fits
from astropy import units as u
hdul = fits.open("path/to/observation.fits")
image_data = hdul[0].data
hdul.close()
distance = 4.2 * u.au
print(distance.to(u.pc))Why would a non-developer care?
Every striking image of a nebula or exoplanet discovery announcement you’ve seen likely passed through analysis pipelines that lean on tools like Astropy somewhere along the way, even though the announcement never mentions the software. It matters because scientific progress depends on researchers trusting and reusing each other’s tools instead of every lab quietly reinventing the same wheel with its own bugs.
Real-world examples
Astropy is used across major astronomical institutions and has been cited in thousands of peer-reviewed astronomy papers. It’s built and maintained by a broad community of professional astronomers rather than a single company, reflecting how deeply embedded it’s become in the field. NASA-affiliated and university observatory teams have incorporated it into data analysis pipelines for telescope observations.
Who uses it
Professional and amateur astronomers, astrophysics researchers, and university astronomy departments doing data analysis on telescope observations.
How it compares to alternatives
Astropy is the de facto community standard for general astronomy computing in Python, whereas older tools like IRAF, once dominant, were harder to use and maintain, part of why the field consolidated around Astropy over the last decade or so.