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Data Processing Software

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Gemini Data Reduction Software

Gemini offers data reduction software for its facility instruments. The Gemini IRAF package and the DRAGONS platform are the official data reduction software supported by Gemini.

For the next several years we will be transitioning from the IRAF platform to our new Python-based DRAGONS platform. As time goes by, more and more instruments and modes will be supported by DRAGONS. During this transition, it is possible that users will require both platforms depending on the data they have obtained.

  • Latest version of Gemini IRAF:  v1.14  (July 2017)
  • Latest version of DRAGONS:  v2.1.1  (April 2020)

Which platform should I use?

Gemini IRAF currently still support all the instruments and modes. However for any imaging data from current instruments, we recommend using DRAGONS. DRAGONS currently support imaging data reduction, but does not support any spectroscopy, for now.

GMOS Imaging DRAGONS (recommended), Gemini IRAF
NIRI Imaging DRAGONS (recommended), Gemini IRAF
GNIRS Keyhole Imaging DRAGONS
Flamingos-2 Imaging DRAGONS (recommended), Gemini IRAF
GSAOI Imaging DRAGONS (recommended), Gemini IRAF, plus Disco-Stu
Any spectroscopy Gemini IRAF
Decommisioned Instruments Gemini IRAF

Download and Install

DRAGONS and Gemini IRAF, support software and dependencies, are all installed the same way using the Anaconda distribution system. We also make use of the STScI Astroconda suite to install common astronomy tools, like ds9.


Gemini IRAF
  • Python 2.7   (for PyRAF)
  • 32-bit compatibility libraries
  • Linux, equilvalent to CentOS 6 and above
  • Or Mac OS X 10.10 to 10.14.0
  • Python 2.7 or 3.6
  • Linux, equivalent to CentOS 6 and above
  • Or Mac OS X 10.10 and above

Please note that it is becoming more and more difficult to package DRAGONS for Python 2.7 and the day is approaching when we will have to drop support for Python 2.7 in DRAGONS.  Also, the spectroscopy support under development is Python 3-compatible only.  We encourage users to start using Python 3 for anything Python to smooth the transition later.  

See the installation instructions here:



Virtual machine image for running IRAF under recent MacOS releases
May 19, 2020

A CentOS 7 virtual machine image (OVA file) is now available to facilitate running Astroconda IRAF under MacOS 10.15+, which no longer supports running the necessary 32-bit binaries natively. This comes with Anaconda 2019.10, Gemini IRAF 1.14, DRAGONS 2.1.0 and other packages from Astroconda pre-installed. Users of MacOS 10.14 affected by the Tk bug that causes a desktop session logout when displaying graphics may also want to install this guest distribution as a workaround.

Please see instructions at

New DRAGONS Patch Release
April 20, 2020

A bug fix release of DRAGONS is now available. In release 2.1.1, we have fixed bugs and typos found by the users and ourselves since the initial release. We have also added compatibility with astropy v4. If you already have DRAGONS installed, you can update by doing conda install dragons=2.1.1. If you need to install DRAGONS for the first time, please see the Download and Installation Instructions.

This update also contains an update of disco_stu.

For information and tutorials on DRAGONS, see the "DRAGONS Information" section.

DRAGONS First Public Release!
October 31, 2019

It is with great delight that we are announcing the first public release of Gemini's new Python-base data reduction platform, DRAGONS, Data Reduction for Astronomy from Gemini Observatory North and South. This project has been many years in the making. DRAGONS offers a more streamlined approached to the data reduction of Gemini data, compared to the Gemini IRAF package.

This release, version 2.1.0, supports imaging reduction only, for the current facility instruments. For spectroscopy data, please continue to use Gemini IRAF for the time being. Work is on-going regarding spectroscopy-support in DRAGONS but it will be a while before it is publicly available for science-quality reduction.

To download DRAGONS:   Download and Installation Instructions

For information and tutorials on DRAGONS, see the "DRAGONS Information" section.

IMPORTANT: MacOS 10.14.6 and 10.15 incompatibilities with data reduction software
October 11, 2019

As of this week's v10.15 release, MacOS is no longer capable of running the 32-bit Astroconda IRAF distribution needed by Gemini IRAF. For the time being, Gemini IRAF users on Apple machines are advised to continue using MacOS 10.14 or earlier, or to install Astroconda in a virtual machine with a compatible OS. Gemini will look into providing a ready-made VM image to help with this while we are migrating our data reduction tools to Python. Furthermore, MacOS 10.14.6 suffers from a bug that can cause a desktop session logout when attempting to display plots or images with PyRAF, DS9, Matplotlib or other software that uses Tk. We suggest that PyRAF users on 10.14 avoid updating their OS until such time as this problem is resolved by Apple and/or we can determine a reliable workaround (check here for further announcements). IRAF CL is unaffected, but note that we are no longer testing it routinely and are aware of occasional failures with Gemini IRAF.

For older announcements, see the Announcements page.

Gemini IRAF Information

Use Gemini IRAF to reduce Gemini facility instrument data, including decommissioned instruments. Get to the Gemini IRAF page for a Description of the package, details of its content, and list of releases and revision history.

However, for imaging data from currently active instruments, we recommend the use of DRAGONS (below) instead.

DRAGONS Information

Use DRAGONS to reduce imaging data from the currently active Gemini facility instruments: GMOS, NIRI, Flamingos-2, GSAOI, GNIRS (keyhole). For spectroscopy data, you must use Gemini IRAF.

The DRAGONS documentation is hosted on

DRAGONS Documentation

Science quality verification for DRAGONS imaging modes is discussed in this report.

The primary reference to be cited by users of DRAGONS is:

        K. Labrie et al. ADASS XXVII, ASP Conf. Ser. 522, eds. P. Ballester, J. Ibsen, M. Solar & K. Shortridge, p. 321

Other Gemini Data Reduction Software

  • Disco-Stu - Distortion Correction and Stacking Utility

    Disco-Stu is a software package for GSAOI images. This standalone package, written in python, will align and stack images that have already been processed by DRAGONS or the Gemini IRAF gareduce task. The current release is v1.3.7.
    To install:

    conda install disco_stu

    Note that disco_stu is installed by default when doing a full install of Gemini IRAF and DRAGONS with conda.


    Disco-Stu Manual
  • gemini_calmgr - Gemini Local Calibration Manager

    The Gemini Local Calibration Manager, gemini_calmgr, is a python package that DRAGONS uses to associate data to reduce with the best processed calibration available. The Local Calibration Manager handles a lightweight database where the users can upload information about the processed calibration they have produced. DRAGONS can then use the calibration association rules to identify and retrieve automatically the master bias, the master flat, etc. that the data requires. The calibration association rules are the same as those used in the Gemini Observatory Archive.

    The package gemini_calmgr is installed automatically as part of a DRAGONS installation.

Need help?

To get help with Gemini IRAF or DRAGONS, please use the Gemini Helpdesk system. Use the Gemini IRAF category even for DRAGONS questions.

     Submit Helpdesk Ticket

If you find a bug with DRAGONS, please consider reporting on the DRAGONS Github issues portal. You will need a Github account.

     DRAGONS Code Issues

For comment, suggestions, and general feedback on DRAGONS, please add a comment to this decidicated post on the Gemini Data Reduction User Forum.

     DRAGONS Feedback Forum