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).

APLpy is a Python module aimed at producing publication-quality plots of astronomical imaging data in FITS format. The module uses matplotlib, a powerful and interactive plotting package. It is capable of creating output files in several graphical formats, including EPS, PDF, PS, PNG, and SVG.

Main features:

• Make plots interactively or using scripts

• Show grayscale, colorscale, and 3-color RGB images of FITS files

• Generate co-aligned FITS cubes to make 3-color RGB images

• Make plots from FITS files with arbitrary WCS (e.g. position-velocity)

• Slice multi-dimensional FITS cubes

• Overlay any number of contour sets

• Overlay markers with fully customizable symbols

• Plot customizable shapes like circles, ellipses, and rectangles

• Overlay ds9 region files

• Overlay coordinate grids

• Show colorbars, scalebars, and beams

• Customize the appearance of labels and ticks

• Hide, show, and remove different contour and marker layers

• Pan, zoom, and save any view as a full publication-quality plot

• Save plots as EPS, PDF, PS, PNG, and SVG

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

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

This package implements a funtionality for hierarchical analysis of strong lensing systems to infer lens properties and cosmological parameters simultaneously. It allows to fit lenses with measured time delays, imaging information, kinematics constraints and standardizable magnifications with parameters described on the ensemble level.

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

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.

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.

POPPY is a Python package that simulates physical optical propagation including diffraction. It implements a flexible framework for modeling Fraunhofer and Fresnel diffraction and point spread function formation, particularly in the context of astronomical telescopes.

POPPY was developed as part of a simulation package for the James Webb Space Telescope, but is more broadly applicable to many kinds of imaging simulations. It is not, however, a substitute for high fidelity optical design software such as Zemax or Code V, but rather is intended as a lightweight alternative for cases for which diffractive rather than geometric optics is the topic of interest, and which require portability between platforms or ease of scripting.

GalSim is software for simulating images of astronomical objects (stars, galaxies) in a variety of ways.

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.

Astroquery is a package that contains a collection of tools to access online Astronomical data. Each web service has its own sub-package.

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

This package provides a Python library for reading from and writing to FITS files using the CFITSIO library. Among other things, it can

• read and write image, binary, and ascii table extensions;

• read arbitrary subsets of tables in a lazy manner;

• query the rows and columns of a table;

• read and write header keywords;

• read and write Gzip files.

This package provides an astronomical Python package with image processing functions: xyxymatch, geomap.

Skyfield computes positions for the stars, planets, and satellites in orbit around the Earth.

This package provides source-only AOCommon collection of functionality that is reused in several astronomical applications, such as wsclean, aoflagger, DP3 and everybeam.

This package provides a flexible toolbox for observation planning and scheduling. When complete, the goal is to be easy for Python beginners and new observers to to pick up, but powerful enough for observatories preparing nightly and long-term schedules.

Features:

• calculate rise/set/meridian transit times, alt/az positions for targets at observatories anywhere on Earth

• built-in plotting convenience functions for standard observation planning plots (airmass, parallactic angle, sky maps)

• determining observability of sets of targets given an arbitrary set of constraints (i.e., altitude, airmass, moon separation/illumination, etc.)

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 provides a librari for spherical harmonic transforms (SHTs), which evolved from the libpsht library, addressing several of its shortcomings, such as adding MPI support for distributed memory systems and SHTs of fields with arbitrary spin, but also supporting new developments in CPU instruction sets like the Advanced Vector Extensions (AVX) or fused multiply-accumulate (FMA) instructions. The library is implemented in portable C99 and provides an interface that can be easily accessed from other programming languages such as C++, Fortran, Python etc. Generally, libsharp's performance is at least on par with that of its predecessor; however, significant improvements were made to the algorithms for scalar SHTs, which are roughly twice as fast when using the same CPU capabilities.

Supporting paper is available at https://arxiv.org/abs/1303.4945

Software for Calibrating AstroMetry and Photometry is a software that computes astrometric projection parameters from source catalogues derived from FITS images. The computed solution is expressed according to the WCS standard. The main features of SCAMP are:

• compatibility with SExtractor FITS or Multi-Extension FITS catalogue format in input

• generation of WCS-compliant and SWarp-compatible FITS image headers in output

• automatic grouping of catalogues on the sky

• selectable on-line astrometric reference catalogue

• automatic determination of scale, position angle, flipping and coordinate shift using fast pattern-matching

• various astrometric calibration modes for single detectors and detector arrays

• combined astrometric solutions for multi-channel/instrument surveys

• highly configurable astrometric distortion polynomials

• correction for differential chromatic refraction

• proper motion measurements

• multi-threaded code that takes advantage of multiple processors

• VOTable-compliant XML output of meta-data

• XSLT filter sheet provided for convenient access to metadata from a regular web browser

H5plot is a small GUI to view the solutions in an H5parm interactively. It is a spiritual successor to ParmDBplot for quickly reviewing gain solutions generated by NDPPP.

Package Raccoon cleans the "wiggles" (i.e., low-frequency sinusoidal artifacts) in the JWST-NIRSpec IFS (integral field spectroscopy) data. These wiggles are caused by resampling noise or aliasing artifacts.