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.
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.
SAOTrace is a suite of software designed to simulate the as-built performance of grazing-angle X-ray optics using the ray-tracing approach. It is derived from portions of the NASA OSAC (Optical Surface Analysis Code) software suite. It can model nested conical as well as flat optical designs, and includes the ability to model arbitrary support structures and baffles. It can model non-ideal multi-layer reflective coatings as well as scattering from the optical surfaces.
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.
AstroStack is an easy-to-use astronomical imaging and processing tool geared towards the use of inexpensive webcam CCDs. It provides a very tunable environment to produce the best quality images. It supports the following features: tunable webcam sampling; image stacking (averaging, additive etc.); pre and post-capture gamma (brightness) and contrast correction; dark-shot CCD calibration (subtractive); and an internal 16-bit grey-scale format for optimal resolution.
IRAF is the Image Reduction and Analysis Facility, a general purpose software system for the reduction and analysis of scientific data. IRAF includes a selection of programs for general image processing and graphics applications, plus a large number of programs for the reduction and analysis of optical astronomy data within the NOAO package. External or layered packages are also available for the analysis of HST, XRAY, and EUV data. IRAF provides a programming environment which includes the Command Language script facility, the IMFORT Fortran programming interface, and the SPP/VOS programming environment in which the portable IRAF system is written.