romanisim is a Galsim-based simulator of imaging data from the WFI on the Nancy Grace Roman Space Telescope (pronounced roman-eye-sim, stylized Roman I-Sim). It uses Galsim to render astronomical scenes, WebbPSF to model the point spread function, and CRDS to access the calibration information needed to produce realistic WFI images.

This package provides ASDF schemas for validating coordinates tags. Users should not need to install this directly; instead, install an implementation package such as asdf-astropy.

astrodata is a package for managing astronomical data through a uniform interface. It is designed to be used with the Astropy package. astrodata was created for use as part of the DRAGONS data reduction pipeline, but it is now implemented to be useful for any astronomical data reduction or analysis project.

Unlike managing files using the astropy.io.fits package alone, astrodata is designed to be extendible to any data format, and to parse, respond to, and store metadata in a consistent, intentional way. This makes it especially useful for managing data from multiple instruments, telescopes, and data generation utilities.

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.

CZML3 is a Python library to write CZML, a JSON format for describing a time-dynamic graphical scene, primarily for display in a web browser running Cesium.

This package implements functionality of spectroscopic reduction in observations from Optical and Near-infrared spectroscopy instruments.

The iers package provides access to the tables provided by the International Earth Rotation and Reference Systems service, in particular the Earth Orientation data allowing interpolation of published UT1-UTC and polar motion values for given times. The UT1-UTC values are used in Time and Dates (astropy.time) to provide UT1 values, and the polar motions are used in astropy.coordinates to determine Earth orientation for celestial-to-terrestrial coordinate transformations.

PypeIt is a Python package for semi-automated reduction of astronomical spectroscopic data. Its algorithms build on decades-long development of previous data reduction pipelines by the developers.

It is designed to be used by both advanced spectroscopists with prior data reduction expertise and astronomers with no prior experience of data reduction. It is highly configurable and designed to be applied to any standard slit-imaging spectrograph, including long-slit, multi-slit, as well as cross-dispersed echelle spectra.

The drizzle library is a Python package for combining dithered images into a single image. This library is derived from code used in DrizzlePac. Like DrizzlePac, most of the code is implemented in the C language. The biggest change from DrizzlePac is that this code passes an array that maps the input to output image into the C code, while the DrizzlePac code computes the mapping by using a Python callback. Switching to using an array allowed the code to be greatly simplified.

Astro-SCRAPPY is designed to detect cosmic rays in images (numpy arrays), based on Pieter van Dokkum's L.A.Cosmic algorithm. Much of this was originally adapted from cosmics.py written by Malte Tewes. This is designed to be as fast as possible so some of the readability has been sacrificed, specifically in the C code.

This package implements a functionality for analysing absorption and emission lines in 1-D spectra, especially galaxy and quasar spectra.

SEP makes the core algorithms of sextractor available as a library of stand-alone functions and classes. These operate directly on in-memory arrays (no FITS files or configuration files). The code is derived from the Source Extractor code base (written in C) and aims to produce results compatible with Source Extractor whenever possible. SEP consists of a C library with no dependencies outside the standard library, and a Python module that wraps the C library in a Pythonic API. The Python wrapper operates on NumPy arrays with NumPy as its only dependency.

This package provides a Glue plugin which adds a 3D scatter plot viewer and a 3D volume rendering viewer.

Python library doing sunrise and sunset time calculation. Takes a WGS84 (GPS) latitude/longitude as input as well as an UTC or local datetime object.

The concept of the pvextractor package is simple - given a path defined in sky coordinates, and a spectral cube, extract a slice of the cube along that path, and along the spectral axis, producing a position-velocity or position-frequency slice.

SNCosmo is a Python library for supernova cosmology analysis. It aims to make such analysis both as flexible and clear as possible.

Generalized World Coordinate System (GWCS) is an Astropy affiliated package providing tools for managing the World Coordinate System of astronomical data.

GWCS takes a general approach to the problem of expressing transformations between pixel and world coordinates. It supports a data model which includes the entire transformation pipeline from input coordinates (detector by default) to world coordinates.

Python read-only implementation of the EventIO file format.

This package provides a replacement for IRAF STSDAS SYNPHOT and ASTROLIB PYSYNPHOT, utilizing Astropy covering instrument specific portions of the old packages for HST.

SPLASH is visualisation tool for Smoothed Particle Hydrodynamics (SPH) simulations in one, two and three dimensions, developed mainly for astrophysics. It uses a command-line menu but data can be manipulated interactively in the plotting window.

STWCS provides support for WCS distortion models and coordinate transformation for the imaging instruments on the Hubble Space Telescope).

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.

PyVO is a package providing access to remote data and services of the Virtual observatory (VO) using Python.

PyCPL provides Python3 language bindings for the complete programming API of the European Southern Observatory Common Pipeline Library toolkit, including the CPL plugin interface.