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 October 2023: TOI-4600c

The TESS lightcurves of TOI 4600 from Mireles et al. 2023. The green triangles show the transits of the smaller planet closer in (TOI-4600b), while the pink triangles show the transits of TOI-4600c.

TOI-4600c is a planet that orbits its star at a similar distance as the Earth orbits the Sun. However, this planet is much larger than the Earth and actually a gas giant! It has a smaller (but still a gas giant) sibling planet closer in towards its Sun as well, which has been observed to transit quite a few times.

However, NASA’s planet hunting satellite TESS (Transiting Exoplanet Survey Satellite) only observed two transits of TOI-4600c in 2019 and again in 2022. That alone is not enough for a definitely classification. Just recently in August of this year though, scientists confirmed its existence with additional observations! In fact, that confirmation makes TOI-4600c the longest-period confirmed planet to be discovered by TESS.

Despite the good news, scientists still need help nailing down the period of this planet, or how long it takes it to orbit its star. Current estimates place the period at 482.82 days, although there is a very small chance that the period could be twice that. So, scientists need to confirm once and for all that this is the period! If a 482 day orbital period is accurate, October 16/17 is the last chance to observe the transit until February of 2025. So make sure you catch the transit this time around! By observing this transit you can observe a history-making exoplanet, one that is a good candidate to be observed by JWST for atmosphere characterization. In addition, TOI-4600c is a planet somewhere between a hot/warm Jupiter and the gas giants of our own solar system, so studying it further could be eye-opening in regards to planet formation.

This is a Northern Hemisphere only target. It is a long-duration transit lasting 11 hours and 8 minutes, so the global UNITE network can really excel! Observations taking place between October 16 10:56 UTC and October 17 09:22 UTC will be useful. However, the transit is expected to begin at Oct. 16 16:30 UTC and end at 03:38 UTC on the 17th. The most important observations will be those surrounding the beginning (ingress) and end (egress). So those in the Middle East / Eastern Asia and North America – we are counting on you! See the spinning globe visual below to see when the transit is visible at your location, and which part of the transit you will be able to observe based on the light curve animation.

How you can help refine the orbit of TOI-4600c

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.
  2. When it is time to start your observation, click this deeplink from the device controlling your telescope and 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: 17h 13m 48s
    Declination: +64° 33′ 58”
    Duration: 04h 00m 00s (recommended)
    Exposure time: 3970 ms
    Gain: 30 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 Sunday October 16 at 10:56 (UTC) and ends on Monday October 17 at UTC 09:22 (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).