Downloading from the Gemini Observatory Archive

For this tutorial we provide a pre-made package with all the necessary data. Here we show how one can search and download the data directly from the archive, like one would have to do for their own program.

If you are just interested in trying out the tutorial, we recommend that you download the pre-made package (Downloading the tutorial datasets) instead of getting everything manually.

Step by step instructions

For this tutorial we selected data observed for for the GS-2017A-Q-29 program on the night starting on May 04, 2017.

Science data

Access the GOA webpage.

In the search form, enter the following information:

  • Program ID: GS-2017A-Q-29
  • UTC Date: 20170504-20170505
  • Obs. Class: science

The search will return 16 files. Download them all by pressing the “Download all 16 files” button at the bottom.


Matching calibration files can be obtained by clicking on the Load Associated Calibrations tab. For this data, domeflats (lamp on and off) and a standard star observation.

The first four files are the standard star sequence. The other files are the lamp on and lamp off domeflats.

The table returned by the automatic calibration association has all that we need. Download everything by pressing the “Download all 34 files” button at the bottom.


Now, copy all the .tar files to the same place in your computer. Then use tar and bunzip2 commands to decompress them. For example:

$ cd ${path_to_my_data}/
$ tar -xf gemini_data.tar
$ bunzip2 *.fits.bz2

(The tar files names may differ slightly depending on how you selected and downloaded the data from the Gemini Archive.)


If you are using the manually selected data to run the tutorial, please remember to put all the data in a directory called playdata, and create a parallel directory of running the tutorial called playground. The tutorial makes assumption as to where everything is located.