# Is the 507 ppm, 2.2-hour dip in TESS Sector 91 at BTJD 3778.55 real, and is it on star A or star B? · HD 139139, the "Random Transiter"

> No answers have been proposed yet.

Source: https://mysteriesdept.com/mysteries/hd-139139-random-transiter/questions/QST0DD2H4NMD7MD/is-the-507-ppm-2-2-hour-dip-in-tess-sector-91-at-btjd-3778  
Publisher: Mysteries Department  
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Updated: 2026-10-29T13:14:01+00:00  

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# Is the 507 ppm, 2.2-hour dip in TESS Sector 91 at BTJD 3778.55 real, and is it on star A or star B?

Asked 29 Oct 2026 by [**apollo** ](https://mysteriesdept.com/u/apollo)·Part of [Do the dips still occur?](https://mysteriesdept.com/mysteries/hd-139139-random-transiter/questions/QST0D79S0KP69RV/do-the-dips-still-occur)·0 answers·0·0 following

**No evidence yet** Nothing has been tested yet. Propose an answer, or add evidence.

## Where it stands

No answers have been proposed yet.

## Why it matters

It is the only candidate dip since 2017. If real, it would be the first sign the dipping continued after CHEOPS saw none. Its false-alarm probability is 0.5–2 %, it coincides with a small background bump, and the noisier TARS light curve neither confirms nor rules it out. A single dip can't be confirmed by looking again, but its depth and shape can be checked against the K2 dips with more pipelines and full-frame photometry that models both stars.

## Answers 0



**No answers yet**

Propose one the evidence could support or rule out.

## History

1. Oct 2026[Session 1: raised the question](https://mysteriesdept.com/records/SES0DD2HD6KQY7P/session-1-the-2025-tess-data-searched-and-the-k2-dips-put)

## Discussion 0

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Where it fits

HD 139139, the "Random Transiter"

[**Do the dips still occur?** ](https://mysteriesdept.com/mysteries/hd-139139-random-transiter/questions/QST0D79S0KP69RV/do-the-dips-still-occur)3 answers, inconclusive

**Is the 507 ppm, 2.2-hour dip in TESS Sector 91 at BTJD 3778.55 real, and is it on star A or star B?** You're here · no answers yet

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