Tutorial to become a Comet Watcher

First time observing a comet? Read this page to master your Unistellar telescope and join our team of Comet Watchers.


1. Select your mission

The visit of a comet is a rare event. To begin watching the comet, you first need to select a mission suitable for your observing location. Go to our Cometary Missions Page and select a comet you want to observe. Your ability to participate in the scientific mission may depend on which hemisphere you are observing from! 

    2. Read the prediction

    Comets are fast-moving targets to observe. Their coordinates in the sky depend on the location and date of the observation. If the comet is in the Unistellar App Catalog, then you will have access to the coordinates from the catalog. However, if the comet is not in the Unistellar App Catalog, you have to compute its celestial coordinates with our Comet Ephemerides page. The recording parameters, Record duration, Exposure Time and Gain, are always given on the Cometary Missions Page.

    3. Moving Target Ephemerides (optional)

    If you want to observe a comet that is not in the Unistellar App Catalog, visit our Comet Ephemerides page. In the Ephemeris Parameters section, select your target and enter the location where you’ll be observing, as well as the date and local time when you’ll be observing. 

    Click on Generate to get your results. After a few seconds, the Ephemeris Results section will be generated with a list of celestial coordinates for your night. Each line corresponds to the position of your target at a specific time.

    If your target is visible from your location, you will be able to click on the smartphone icon (Deep Link) that will open your Unistellar App and fill the Cometary Activity section with the proper fields. If your target is not visible, a crossed-out eye icon will appear. You need to save these coordinates for your observation or you will have to compute them during your observation.


    We recommend observing the comet with the enhanced vision mode first to see the comet and its coma live for 10 to 20 minutes, and then to repeat the observation within the scientific mode to help scientists

    1. 10 minutes before the mission

    It is time to point to your target. Two options:

    It is time to point to your target. You have two options depending on whether or not the comet is in the App Catalog.

    A. The comet is in the catalog: Open your Unistellar App, in the Catalog, enter the name of your comet, select it and click on Goto. Once the goto is Done,  click on the Science menu and select the Cometary Activity tab. Skip the step that prompts you to Point to the Target. Enter the Record duration, Exposure time, and Gain – then click on Save.


    B. The comet is NOT in the App Catalog: The quickest way to find your target is to use your smartphone to click on the Deep Link generated with our Comet Ephemerides tool that you read about in the previous section.  It will automatically open the Cometary Activity tab of your Unistellar App to enter the coordinates of the target and its recording parameters. If the Right ascension box and Declination box are filled with the correct coordinates, click on Goto to point to your target. Once Goto is done, if the Record duration, Exposure time, and Gain are correct, you can click on Save.

    2. Launch observation

    You have the choice to first observe the comet and its coma with the enhanced vision mode or to directly collect scientific data. To collect scientific data, repeat the previous step. When you are ready, click on the Record button to start the observation.

    During the observation, you may see the comet moving. 

    3. Complete observation

    Once the recording is over, click on Continue to calibrate your sensor. This calibration step gathers Dark Frames, which will help us better analyze your observation. You must put the dust cap on your telescope before recording the calibration.

    After this step, a final message appears: “Recording complete”. The mission is over.


    1. Share your data

    Once you are at home, please upload your data to our server. Our team of scientists will analyze your observation to check if you detected the occultation. If you need help, please read these guidelines on “how to upload my data”.

    2. Tell Unistellar you participated

    To make sure your contribution is properly processed and you are credited for the result, always fill out this Comets Observation Report. It asks for your name, the serial number of your telescope, and the name of the scientific mission you just accomplished. 

    We will send you the result of your scientific mission through our Slack communication platform within 24 hours.

    Great Work, Citizen Astronomer.