Citizen Astronomers around the world will have another chance to spot and confirm the existence of a brand new exoplanet this August. But they’ll need a little bit of luck this time to catch the planet TOI 4465.01 transit, or pass in front of, its star: Unlike other exoplanets, there aren’t precise estimates of TOI 4465.01’s orbit. That means the exoplanet transit could be visible at any point over a three day window beginning August 9 (see more details below). That also means we’ll need observations from people all over the world to get to the bottom of this puzzle!

TOI 4465.01 is an “Object of Interest” discovered in 2021 by NASA’s TESS satellite, which searches for exoplanets. This behemoth planet candidate, thought to be six times more massive than Jupiter, has only been observed by TESS once, so scientists still need to confirm that it’s real. To help, a team led by Unistellar astronomers has been observing this Sun-like star to watch the tiny variations in motion caused by the planet’s gravity tugging it back and forth – a phenomenon separate from transits, known as the “Doppler effect”. Based on their data so far, astronomers believe TOI 4465.01 will transit in front of its star during this three day window.

Disclaimer: The material contained in this document is based upon work supported by a National Aeronautics and Space Administration (NASA) grant or cooperative agreement. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of NASA.

TOI 4465.01 orbits its star roughly once every 101 days. That puts its next transit sometime between August 9 and August 11. We’ll need observations covering that entire timeframe, plus an additional 12 hours before and after it (to establish the “normal” brightness of the star) if we’re going to nail down the object’s orbit! And because the observation window is so long, we need contributions from Unistellar Network members in multiple regions to capture the entire span.

As an exoplanet passes in front of its star, it blocks out a portion of the star’s light.

If we see a transit in August, it will help determine TOI 4465.01’s existence and period, or how long it takes to orbit its star, which in turn gives researchers a better idea of what the atmosphere on this distant world might be like. It will also be only the second recorded transit for this object and the very first observed from the ground!

How you can observe TOI 4465.01 and contribute data:

If this is your first time doing an exoplanet observation, find tips and tricks on our Tutorial page. This specific observation will be a little different than usual, so the observing information is given below instead of on our Exoplanet Predictions page.

Observers can point their eVscopes toward TOI 4465.01 at any time during the three-day span when the transit may occur. Check out the spinning-globe video for a visual — you can observe when your location is in the red-shaded portion of Earth. The first possible observations are on the local evening of Thursday, August 8 (from North and South America) and the last are on the local evening of Thursday, August 11. In its entirety, the window for helpful observations begins on Tuesday, August 9 at UTC 01:59 and ends on Friday, August 12 at UTC 01:59. Nearly every location on Earth gets at least two nights to observe this event, except for the very most northern and southern points. We hope you’ll join us with your Unistellar telescopes!

A globe showing the visibility of TOI 4465.01’s transit. If you are in the shaded region during the time displayed, you can make an observation.

Observation Details:

Citizen Astronomers should observe for at least 4 hours continuously (but feel free to observe for longer!) in Exoplanet Transit mode. Note that the full Moon will be relatively near the target star – this should not pose a problem.

You may click on this deeplink to automatically set up 1 hour observations that you can repeat as many times as you like.

OR you can manually input these settings in Exoplanet Transit mode:

Right ascension (RA): 18h 24m 32s
Declination (Dec): 15° 50′ 31″

Record duration: 01h 00m 00s  (or set to your desired length; at least 4 hours is best, but please monitor the position of the star and re-center if needed)

Exposure Time: 3970 ms
Cadence: 3970 ms
Gain: 11 dB

Lastly, when you are done observing for the night, please submit this short REPORT FORM so we know to process your data.

Clear skies!

If you have any questions, please reach out to us at [email protected] or on our Citizen Science Slack workspace.

Further readings