Astropy is a single core package for Astronomy in Python. It contains much of the core functionality and some common tools needed for performing astronomy and astrophysics.

This package implements a functionality to match sky on image mosaic.

The ccdproc package provides many of the necessary tools for processing of CCD images built on a framework to provide error propagation and bad pixel tracking throughout the reduction process.

tweakwcs is a package that provides core algorithms for computing and applying corrections to WCS objects such as to minimize mismatch between image and reference catalogs. Currently only aligning images with FITS WCS and JWST gWCS are supported.

Fitsverify is a computer program that rigorously checks whether a FITS data file conforms to the requirements defined in Version 3.0 of the FITS Standard document.

ZodiPy is an package for simulating zodiacal light in intensity for arbitrary solar system observers.

This is a library implementing the simplified perturbations model. It can be used to calculate the trajectory of satellites.

This package provides a Python definition and validation schemata for FITS files.

CFITSIO provides simple high-level routines for reading and writing Flexible Image Transport System files that insulate the programmer from the internal complexities of the FITS format. CFITSIO also provides many advanced features for manipulating and filtering the information in FITS files.

Event reconstruction framework for Imaging Atmospheric Cherenkov Telescopes developed for CTAO.

skyfield computes positions for the stars, planets, and satellites in orbit around the Earth. Its results should agree with the positions generated by the United States Naval Observatory and their Astronomical Almanac to within 0.0005 arcseconds (half a mas or milliarcsecond).

This packages provides a calibration software for COS.

Ginga is a toolkit designed for building viewers for scientific image data in Python, visualizing 2D pixel data in numpy arrays. It can view astronomical data such as contained in files based on the FITS (Flexible Image Transport System) file format. It is written and is maintained by software engineers at the National Astronomical Observatory of Japan (NAOJ), the Space Telescope Science Institute (STScI), and other contributing entities.

The Ginga toolkit centers around an image display object which supports zooming and panning, color and intensity mapping, a choice of several automatic cut levels algorithms and canvases for plotting scalable geometric forms. In addition to this widget, a general purpose "reference" FITS viewer is provided, based on a plugin framework. A fairly complete set of standard plugins are provided for features that we expect from a modern FITS viewer: panning and zooming windows, star catalog access, cuts, star pick/FWHM, thumbnails, etc.

This package provides a Python module to various STScI image array manipulation functions.

This package implements functionality for simulating X-ray emission from astrophysical sources.

X-rays probe the high-energy universe, from hot galaxy clusters to compact objects such as neutron stars and black holes and many interesting sources in between. pyXSIM makes it possible to generate synthetic X-ray observations of these sources from a wide variety of models, whether from grid-based simulation codes such as FLASH, Enzo, and Athena, to particle-based codes such as Gadget and AREPO, and even from datasets that have been created 'by hand', such as from NumPy arrays. pyXSIM also provides facilities for manipulating the synthetic observations it produces in various ways, as well as ways to export the simulated X-ray events to other software packages to simulate the end products of specific X-ray observatories.

The GNU Astronomy Utilities (Gnuastro) is a suite of programs for the manipulation and analysis of astronomical data.

CalcMySky is a software package that simulates scattering of light by the atmosphere to render daytime and twilight skies (without stars). Its primary purpose is to enable realistic view of the sky in applications such as planetaria. Secondary objective is to make it possible to explore atmospheric effects such as glories, fogbows etc., as well as simulate unusual environments such as on Mars or an exoplanet orbiting a star with a non-solar spectrum of radiation.

This package consists of three parts:

• calcmysky utility that does the precomputation of the atmosphere model to enable rendering.

• libShowMySky library that lets the applications render the atmosphere model.

• ShowMySky preview GUI that makes it possible to preview the rendering of the atmosphere model and examine its properties.

This package provides ALFA, which can identify and fit hundreds of lines in emission line spectra in just a few seconds with following features:

• A population of synthetic spectra is generated using a reference line catalogue.

• The goodness of fit for each synthetic spectrum is calculated. The best sets of parameters are retained and the rest discarded.

• A new population of synthetic spectra is obtained by averaging pairs of the best performers.

• A small fraction of the parameters of the lines in the new generation are randomly altered.

• The process repeats until a good fit is obtained.

pyregion is a python module to parse ds9 region files. It also supports ciao region files. Features:

• ds9 and ciao region files.

• (physical, WCS) coordinate conversion to the image coordinate.

• convert regions to matplotlib patches.

• convert regions to spatial filter (i.e., generate mask images)

MARTINI is a modular package for the creation of synthetic resolved HI line observations (data cubes) of smoothed-particle hydrodynamics simulations of galaxies. The various aspects of the mock-observing process are divided logically into sub-modules handling the data cube, source, beam, noise,spectral model and SPH kernel. MARTINI is object-oriented: each sub-module provides a class (or classes) which can be configured as desired. For most sub-modules, base classes are provided to allow for straightforward customization. Instances of each sub-module class are given as parameters to the Martini class; a mock observation is then constructed by calling a handful of functions to execute the desired steps in the mock-observing process.

Astrolib PySynphot (hereafter referred to only as pysynphot) is an object-oriented replacement for STSDAS SYNPHOT synthetic photometry package in IRAF. pysynphot simulates photometric data and spectra as they are observed with the Hubble Space Telescope (HST). Passbands for standard photometric systems are available, and users can incorporate their own filters, spectra, and data.

This package provides base classes and command-line tools for implementing calibration pipeline software.

LibXISF is C++ library that can read and write XISF files produced by PixInsight. It implements XISF 1.0 specification.

The Advanced Scientific Data Format (ASDF) is a next-generation interchange format for scientific data. This package contains the Python implementation of the ASDF Standard.