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Yesterday I was going through the TESS mission data on mast portal and after applying some filters I found some data. I started analyzing that data using the lightkurve library.

plot without using the periodogram script: enter image description here

Running all the scripts I found this plot:

enter image description here

Then I searched after this star system on the exomast archive portal just to check that this system wasn't analyzed earlier by researchers and I am not wasting my time. The portal didn't show any results which means that TESS researchers haven't studied this one yet and was not confirmed as an exoplanet.

Does this mean that I found it?

And what should I do now with this?

If this was already known I have no problem, this was fun to analyze.

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  • $\begingroup$ After your updated question, this looks like a Hot (~4 days period) Jupiter (~1% transit depth around an F8 main sequence), but confirmation of a planetary mass companion would need a lot more work, as ProfRob has elucidated. $\endgroup$ Commented Oct 9, 2022 at 12:55
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    $\begingroup$ As said in the answer below - you need to exclude false positives (such as eclipsing binaries, background objects) and find radial velocity data that fits the same period and has a mass commensurable with the rough expected mass of a planetary object. Those things are much harder to do though, and specialist pipelines are used for those. I am no expert in those things though. $\endgroup$ Commented Oct 9, 2022 at 13:12
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    $\begingroup$ @AtmosphericPrisonEscape then how should I do this ? pls can u share some resources at least $\endgroup$ Commented Oct 9, 2022 at 13:14
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    $\begingroup$ Frankly, if you don't know... maybe your best bet is to find an astrophysicist who's interested in helping do the next steps? $\endgroup$
    – Joe
    Commented Oct 10, 2022 at 14:33
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    $\begingroup$ If you want to look into it further, you might want to reach out to the AAVSO, they are a "citizen science" organization connecting armature astronomer findings with professionals. aavso.org/exoplanet-section $\endgroup$ Commented Oct 11, 2022 at 12:25

2 Answers 2

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It could be an exoplanet transit (but that doesn't mean it is).

The star in question, TIC92352620, is an F8 main sequence star, which would be much larger than any plausible planet. If a planet transits in front of such a star, you expect a very rapid entry and exit to the eclipse with a flattish bottom, where any curvature can be attributed to limb darkening on the host star. The transit should repeat and look the same each time.

I'd say your potential transit passes that test, so it could be a Jupiter-sized planet on a 4-day orbit.

Even then, there are false positives that can produce similar results (e.g. the presence of a contribution of light from an eclipsing binary star that encroaches within the point spread function of the instrument - i.e. an unrelated star contaminating the data).

As to where you go from here, well, the discovery of an unremarkable transiting exoplanet is of interest, but not really headline news any more. A significant amount of work would remain to confirm the candidate and rule out possible false positives. At the least, because this is a bright star, one should obtain spectroscopy that shows any radial velocity deviations are very small, commensurate with a planetary nature for the companion.

Some information on eliminating (some) false positives in TESS data https://www.zooniverse.org/projects/nora-dot-eisner/planet-hunters-tess/talk/4733/2174551

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  • $\begingroup$ I am very skeptical about this being a exoplanet, an asteroid might be the cause $\endgroup$
    – Alastor
    Commented Oct 9, 2022 at 11:10
  • $\begingroup$ umm just to tell i have folded this plot using the periodogram to get this single dip $\endgroup$ Commented Oct 9, 2022 at 11:35
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    $\begingroup$ @ParamKasana I see. Why is the x-axis labelled as phase, but has units of days?? Anyway, how many transits do you have and do they individually look the same? $\endgroup$
    – ProfRob
    Commented Oct 9, 2022 at 11:45
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    $\begingroup$ sorry, I forgot to change the x-axis label in the resultant plot. Yes individual transit dips look same i will add the plot which is not folded in the post $\endgroup$ Commented Oct 9, 2022 at 12:15
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    $\begingroup$ @ProfRob can u provide some helpful resources to do further analysis (removing false positives, spectroscopy, and radial velocity) i really wanna continue this :) $\endgroup$ Commented Oct 9, 2022 at 14:04
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Really hard to answer, a light-dip doesn't necessarily mean that you actually discovered a exoplanet. There can be multiple reasons to why this was not classified yet.

Asteroid belts can be a reason, multiple large asteroids can cause significant dimming, by obscuring the star's light.

Exoplanets are found by running multiple analyzing processes, such as "wobbling" which means that even a small planet can cause a tiny, yet detectable tug on the star. A light-dip is hardly substantial evidence and can be easily taken for a asteroid belt.

As to what you should do with this discovery (in the unlikely case that you found a exoplanet(, I am afraid that is really hard to understand, as there are really few amateur astronomers who have made a significant discovery. Best bet would be to share the discovery on SIMBAD or some Astronomy catalog.

EDIT: After more information, this sounds more like a Hot Jupiter.

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  • $\begingroup$ Multiple large asteroids? How on earth would that give you such a light curve? $\endgroup$
    – TonyK
    Commented Oct 10, 2022 at 19:10
  • $\begingroup$ @TonyK asteroids are theorized to produce more intense dimmings in Tabbys Star $\endgroup$
    – Alastor
    Commented Oct 11, 2022 at 10:45
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    $\begingroup$ Look at the light curves in this Wikipedia article on Tabby's star. None of them has the near-vertical sides and wide bottom of the OP's observations. $\endgroup$
    – TonyK
    Commented Oct 11, 2022 at 11:52

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