Step 1 - Access the data

To complete your detective’s mission you need to select your target and access the Cheops satellite data. We suggest that you start your mission with KELT-3b.

Astronomers use specific software tools to analyse the data and fit mathematical models. Access the data using one of the two options below.  

Option 1

Download a document with the  exoplanet transit light curve and best model fit already calculated.

Option 2

You can access one of the tools astronomers use to analyse these exoplanets: Allesfitter. This tool is available online, you do not need to install any software in your computer. Watch the video tutorial or download the step-by-step allesfitter guide to learn how to use allesfitter and access the Cheops data.

If you experience slow loading times, you can also download a pdf file with the exoplanet transit light curve and best model fit. 

Download the allesfitter guide:

For step-by-step instructions on how to use allesfitter, follow this useful guide.

Watch the allesfitter mini tutorial:

Play Video

Subtitles are available (automatically generated by YouTube) – select your language using the YouTube player controls.

Once you have analysed the data, you can continue your investigation into the exoplanet’s properties: size, orbital period and distance, temperature and habitability, and composition. When you’re ready to continue to the next step, return to this page and click “continue the investigation“.

Step 1 Complete!

Your Investigation Progress


Have you analysed the Cheops data and found a best fit model for the light curve? If yes, you can continue to Step 2 of your investigation into the exoplanet’s properties, starting with size!