Find an exoplanet transit to observe! Select a region below and choose an event near your location.

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Click on a row to display the event’s visibility map and click here for more explanation.

*** AFTER OBSERVING, please submit this REPORT FORM so we know to process your data. ***

Featured Exoplanet Transit for May 2023: TIC 393818343.01

The initial TESS transit of this exoplanet, uncovered by Citizen Astronomers with the Visual Survey Group.

The giant planet TIC 393818343.01 was first discovered to transit its host star by citizen astronomers combing through data from NASA’s TESS (Transiting Exoplanet Survey Satellite). They discovered the single transit of this planet, shown in the figure above. However, only this one transit signature has ever been observed – so scientists need more data to find out what this exoplanet is all about!

The initial transit, combined with radial velocity data – which shows how the host star wiggles under the influence of the planet – indicate that this is a gas giant that orbits its star every 16 days, making it a “warm Jupiter.” Warm Jupiters orbit their star every 10-200 days at a distance of 0.1 to 0.5 Earth-Sun distances, or astronomical units (AU). But TIC 393818343.01 may not stay warm for long: this exoplanet has a very eccentric, or oblong, orbit that brings it very close to its star. So astronomers think it may be nestling in closer as its orbit becomes more circular, leading it to eventually become a “hot Jupiter.” Hot Jupiters are similar in size and composition to warm Jupiters, but they orbit their star in typically less than 10 days at a distance of only 0.1 AU or less! This can lead to surface temperatures thousands of degrees high, as well as tidal locking, meaning they only show one side of their planetary body towards their Sun, which can lead to extreme and interesting space weather. All in all, to know for certain whether this exoplanet will stay warm or heat up, astronomers need your help catching another transit!

Depending on your location (see the map below), you can catch the exoplanet transit from May 22 – May 23 (UTC). If your location is in the red shaded region at any point of the observation window, you can contribute! The highest priority visibility for this transit occurs in the Middle East and Africa, but all observations are useful!

How you can help refine the orbit of a hot Jupiter in the making, TIC 393818343.01

If this is your first time observing an exoplanet transit with a Unistellar telescope, check out our Get Started page for an overview of the techniques involved. Then:

  1. Play the adjacent spinning-globe animation to find the UTC date and time that your location enters and exits the red shaded region. The entry time is the earliest you can start your observation and the exit time is the latest you can end that observation.
    IMPORTANT: Convert the UTC date & time to your local time zone to make sure you have the right start and end times.
    Multiple observations are possible from every location, so be careful to note the date as well as the time.
  2. When it is time to start your observation, click this deeplink from the device controlling your telescope to observe for at least four hours, which is the minimum recommended observing time. Click “Goto” to point to the target, then “Record” to begin collecting data. Alternatively, you can manually input the “Exoplanet transit” mode recording settings below.
    Right ascension: 20h 41m 10s
    Declination: 03° 38′ 18″
    Duration: 04h 00m 00s (recommended)
    Exposure time: 3970 ms
    Gain: 4 dB
    Cadence: 3970 ms
    Please observe more than 4 hours if you can!
  3. After finishing your science observations, record “sensor calibration” dark frames as instructed in the tutorial.
  4. After you are done observing for the night, please submit this short REPORT FORM so we know to process your data.

In its entirety, the window for helpful observations begins in the evening Monday May 22 at 18:05 (UTC) and ends on Tuesday May 23 at UTC 06:13 (UTC).

You can expect a recap of the event within ~1 week and the preliminary results of your observations within ~1 month.

If you have any questions, please reach out to us at

Predictions Table Explained


  • Blue stars & shading = full visibility (you can observe the entire event)
  • Yellow triangles = full visibility but some tracking difficulty (when target altitude > 70 degrees)
  • Orange diamonds = partial visibility; you may miss the start or end of the event
  • No symbol = no visibility (either the target is not up or it is too close to daytime)
  • Click on a symbol on the map to show precise observation times, target altitudes, and Sun altitudes specific to that location.


  • The Link automatically populates observing settings into the Unistellar app’s “Exoplanet transits” Science menu.
    • Note that these links will only work from your smartphone/tablet with the Unistellar app installed.
  • Finder is an image of the target field of view (your live view may be rotated by comparison).
  • Date is the observation start date in UTC (Coordinated Universal Time).
  • Start UTC is the overall event’s observation start time in UTC. Your own start time may differ — click on the visibility map’s icons for location-specific times.
  • End UTC is the overall event’s observation end time in UTC. Your own end time may differ — click on the visibility map’s icons for location-specific times.
  • Local is the observation start time in the time zone of your device’s browser.
  • eVscope settings are in Exp (exposure time in milliseconds), Gain (in decibels), Cad (cadence in milliseconds), Ra (right ascension), & Dec (declination).