WCSLIB is a C library, supplied with a full set of Fortran wrappers, which implements the "World Coordinate System" (WCS) standard in FITS (Flexible Image Transport System). It also includes a PGPLOT-based routine, PGSBOX, for drawing general curvilinear coordinate graticules, and a number of utility programs. The FITS "World Coordinate System" (WCS) convention defines keywords and usage which provide descriptions of astronomical coordinate systems in a FITS image header.
GRALE is a set of tools - a library and a number of accompanying applications - to study gravitational lenses. Gravitational lenses are astronomical objects so massive that their gravitational pull even deflects light rays. This can cause multiple copies of the same background object to be visible, like a cosmic mirage. The locations and shapes of these copies can provide information about the mass distribution of the gravitational lens, which GRALE can help recover using a genetic algorithm-based method. Apart from these so-called lens inversions, it's also possible to simulate gravitational lenses.
ChiantiPy is a Python interface to the CHIANTI atomic database for astrophysical spectroscopy. The CHIANTI atomic database for astrophysical spectroscopy provides the information necessary to calculate the emission spectrum from hot plasmas. ChiantiPy provides several top-level classes to access the database and calculate continuum and emission line intensities.
Aciqra is a night sky simulator to show the sky and celestial objects. It uses the highly precise Aloac program to calculate highly accurate positions for planets, stars, comets, and everything else in the sky for thousands of years into the future. It can load a variety of catalogs and even custom ones with a bit of extension.
I is a programming language that was designed to be efficient to write and run. The system incorporates many major libraries, allowing the creation of major projects such as Aciqra. It is an interpreted language and supports CGI scripting through the use of the CGI for Aciv/I extension.
AstroAviBrowser is a small tool for astronomy imaging capture/processing. It allows you to open a video file, select the good frames, and save the new sequence in a new avi file using raw or lossless codecs. You may also de-bayer your frames and separate RGB plans. It's a kind of "AviRaw" for Linux.
Qastrocam-g2 is a fork of the Qastrocam project, Webcam capture software for astronomy. This fork adds support for RGB24 (luminance only) and YUYV. It has better generic V4L support (lx mode and resizing). Settings backup has been added. There is better parallel and serial lx mode support. There are a number of other changes and additions.
Sunrise Sunset is a Python package that can determine the sunrise and sunset based on a given altitude zenith. It has two public methods. The first returns the sunrise and sunset in a tuple. The second returns True or False depending on whether the supplied date/time is during the night or day. The constructor takes three arguments, a date, latitude, and longitude. There is one keyword argument for changing the default zenith, which is set to "official". The zeniths are "official", "civil", "nautical", "amateur" (astronomical), and "astronomical". It does not rely on third party packages, but you may need something like pytz to create dates with timezone info.