Free and Open-Source Astronomy Software

Nate Lust's Software

NTV Image Viewer

This is a clone of the popular atv software for the IDL programing language written entirely in python and qt. While attempting feature parody, the features most relevant to the author have been implemented first. If there is a feature you wish to see implemented requests are taken, but doing it yourself will see it done faster! Full details can be found on the project page at

Joe Harrington's Software

Here is a collection of free software packages that implement astronomical methods. Some are relevant to a wider audience as well. Each package stands separately from the others. Open-source licenses apply to all packages, and authors and copying rules are identified in each package.

The packages are provided as a community service on an as-is basis. They include basic documentation, but are intended as reference implementations that others can adapt rather than as blackboxes.  There are no GUIs.  No support is provided nor are any guarrantees made for any of them. (And, as a scientist, you are responsible for the action of all software you use in your research anyway). However, most package authors would welcome a carefully assembled bug report if you do find a problem. Authors are identified in each package, or you can email Prof. Harrington.

If you use this software to any significant degree, we'd appreciate (and sometimes require, see licenses) your saying so in the acknowledgements to papers, and sending us copies of the papers.  This may help us someday get funding for software development.

Some packages are provided in the Interactive Data Language. IDL is not an open-source language, but its array mathematics capability makes it very powerful for astronomical data analysis, so it is widely used. For a popular open-source alternative that is based on the Python language, see

Automatic Image Mosaic Assembly

If you have sets of images that need "stitching", this package might do the job without much intervention by you beyond an approximate initial guess as to relative location.  You can restrict how far it will let the component images move.  Written long before commercial image stitchers were available, it works on FITS files that have no relative rotation or scaling, such as mosaics taken by a telescope.  There is a portion of a paper describing the method included in the tarball.  It is written in C.

Planetary Limb Finder

If you want to map images of planets, you first have to locate the planet precisely.  This package fits a planet's limb, and allows for parameters like the orientation and oblateness to be fixed or free.  It is written in C and works on FITS images.

Removal of Fringes From Images

"Defringeflat" uses a wavelet transform to identify and remove fringe patterns from images such as spectrograph flat fields. It is an IDL package.

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This package requires the file, written and maintained by Torrence and Compo. You can get the latest version from them, and read their paper to learn more about their routine and wavelets in general. The version we used to test our software is here.

Optimal Extraction of Array Spectra

"Optspecextr" uses optimal estimation to determine the spectrum of a point-source object, following Horne (1986, PASP 98:609-617) with some modifications. It is an IDL package.

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Synthetic Array Spectrum Frames

"Synthspec" produces mock data from a spectrograph. It is useful in testing spectral extraction routines. It is an IDL package.

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Mask-Based, Non-Linear Pixel Interpolation

"Maskinterp" repairs bad pixels in an image without using data from other bad pixels, even after they have been fixed. It fits a non-linear surface to good pixels surrounding each marked bad pixel, and increases the number of good pixels included in the fit based on user-controllable criteria with reasonable defaults. It is an IDL package.

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The software disseminated here was written in part under the support of the National Aeronautics and Space Administration and the National Science Foundation.

LaTeX CV Example

This is an example academic Curriculum Vitae (CV), done in LaTeX with BibTeX.  You can look at the CV to get the format used for academic personnel evaluations or even copy it and replace its content for your own use.

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The software disseminated here was written in part under the support
of the National Aeronautics and Space Administration and the National
Science Foundation.

Backup Manager

Who hasn't learned the lesson of backups?  This automagic backup software for Unix/Linux systems schedules nightly backups over your network, prompts someone to change the tape via email, and lets you know if anything went wrong with last night's backup. It uses standard Unix commands to write tapes, so anyone can read them.