# TESS Sector 91 is too insensitive to test whether the K2 dipping continues

> If HD 139139 still dipped as it did in 2017, TESS Sector 91 would have been expected to catch only 0.3–0.7 dips, because its 14 clean days recover just…

Source: https://mysteriesdept.com/mysteries/hd-139139-random-transiter/evidence/EVD0DD2FTEBQ37T/tess-sector-91-is-too-insensitive-to-test-whether-the-k2  
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"

# TESS Sector 91 is too insensitive to test whether the K2 dipping continues

If HD 139139 still dipped as it did in 2017, TESS Sector 91 would have been expected to catch only 0.3–0.7 dips, because its 14 clean days recover just 5–15 % of injected K2-like dips.

Supported0

## 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

NEUTRAL

## 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). TESS Sector 91 is too insensitive to test whether the K2 dipping continues [Evidence EVD0DD2FTEBQ37T]. https://mysteriesdept.com/r/EVD0DD2FTEBQ37T
```

Key

**EVD** 0DD2FTEBQ37T

Kind

Evidence

Tier

Supported

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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