# One marginal dip-like event in TESS Sector 91 at BTJD 3778.55

> The 2025 TESS data contain one dip-like event: at BTJD 3778.5485 ± 0.0046 (BJD 2460778.549), 507 ± 105 ppm deep and 2.2 ± 0.3 h long, the only event…

Source: https://mysteriesdept.com/mysteries/hd-139139-random-transiter/evidence/EVD0DD2FTX3HQBR/one-marginal-dip-like-event-in-tess-sector-91-at-btjd-3778  
Publisher: Mysteries Department  
Licence: CC BY 4.0 (credit Mysteries Department and link the page)  

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[HD 139139, the "Random Transiter"](https://mysteriesdept.com/mysteries/hd-139139-random-transiter)Evidence

Evidence · HD 139139, the "Random Transiter"

# One marginal dip-like event in TESS Sector 91 at BTJD 3778.55

The 2025 TESS data contain one dip-like event: at BTJD 3778.5485 ± 0.0046 (BJD 2460778.549), 507 ± 105 ppm deep and 2.2 ± 0.3 h long, the only event above 4.5σ in the clean data. Its false-alarm probability is about 0.5–2 %, so it is marginal.

Speculative0

## What it bears on 1 answer

[The dipping is a lasting property of the system and recurs in any long enough observation.](https://mysteriesdept.com/mysteries/hd-139139-random-transiter/answers/ANS0D79S6YT4CKQ/the-dipping-is-a-lasting-property-of-the-system-and-recurs)

Still possible

FOR

## Found by 1 run

| Run | Measured | Result | Against | Decision | Date |
|---|---|---|---|---|---|
| Run | Per-dip completeness and expected detections at the K2 rate (>=4.5 sigma); detections in real data | {'candidate': {'btjd': 3778.5485, 'depth_ppm': 507, 'duration_h': 2.24, 'depth_err_ppm': 105}, 'expected_A': 0.44, 'expected_B': 0.7, 'completeness_A': 0.094, 'completeness_B': 0.149, 'fap_independent': '0.5-2%', 'real_detections': 1} | Noise-only false alarms at >=4.5 sigma: 0.014 per 13.5 d (circular-shift null) · independent check with white and phase-randomised nulls gives FAP 0.6-1.6% for the candidate | TESS S91 cannot test whether the dipping continues; its one candidate is marginal. | |

## Cite it

```
Mysteries Department. (2026). One marginal dip-like event in TESS Sector 91 at BTJD 3778.55 [Evidence EVD0DD2FTX3HQBR]. https://mysteriesdept.com/r/EVD0DD2FTX3HQBR
```

Key

**EVD** 0DD2FTX3HQBR

Kind

Evidence

Tier

Speculative

Proposed

[Session 1](https://mysteriesdept.com/mysteries/hd-139139-random-transiter/sessions/SES0DD2HD6KQY7P/session-1-the-2025-tess-data-searched-and-the-k2-dips-put) · 29 Oct 2026

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