Python AstroLib

The aim of this project is to bundle a number of helpful rather small-scale routines. This comprises porting the well-known “IDL Astronomy User’s Library” (AstroLib) to Python. As the corresponding IDL code has been in use for decades now, it is “tested by application”. Therefore, we try to stay as close as possible to the IDL implementation. Furthermore, helpful routines will be added.


This is not an attempt to port the entire IDL library at once. We do what we need! Help is appreciated.

Available functionality

Below, you find a list of available functionality roughly sorted by category.

General algorithms

General data analysis

Spectral routines

Coordinates, time, and observation tools

Transit and planet routines


Resource based helpers

License note

The “IDL Astronomy User’s Library” is released in “public domain”. That means that nobody holds the copyright and, thus, nobody has the right to sublicense it (not even the authors). As we remain as close as possible in code and ship the documentation mainly as is, it would be quite cumbersome to actually assign copyright to parts written by us. Therefore, code which was directly ported from the IDL Astronomy User’s Library is released in public domain and is marked by a note in the respective documentation saying:

This function was ported from the IDL Astronomy User's Library.

All other code not carrying this note (may include fresh implementations of functionality already provided by the IDL Astronomy User’s Library, newly introduced functions, etc.) is released under the MIT license.