13.77-Day Dip: Codex Spotted a Possible Planet Hiding in 17-Year-Old Kepler Data
- Level Advanced
- Setup1–3 hrs (estimated)
- Evidence Some evidence
- CostNot stated in source
- No-codeNo
What they did
A hobbyist used Codex to build tools that scan public NASA Kepler and TESS data for stars that dim on a schedule. It flagged an uncatalogued dip every 13.77 days around KIC 5689121, a small red star about 970 light-years away. It sits 7.1 arcseconds from a much brighter star, which is probably why it was missed. If it's real, it's a planet about 2.5 to 3 times Earth's size, and he published all the evidence online.
How it went
A shortlist of repeating dips in public telescope data, each with plots and an honest false-alarm check.
Worth knowing
- Still only a candidate: his own validation score is about 6.9%, and it needs telescope follow-up (infrared or adaptive-optics imaging, such as Keck) before anyone can call it a planet. The post title says ChatGPT; the post itself says the work was done with Codex.
Prompt
Cleaned version rewritten from the source — not a direct quote.
Help me search public [Kepler / TESS] light curves for possible transiting planets. Download the data for [star or field] with [lightkurve], clean up the trends, run a box least squares search, and flag repeating dips that aren't in the known planet catalogues. For each signal, try hard to prove it is NOT a planet: check nearby bright stars, odd versus even dip depths, and data you held back from the search. Show me the plots and say plainly how likely it is to be a false alarm.
Recommended
Try it in Grok Bot
- Copy the prompt (button below).
- Open Grok Bot chat and paste it. Replace any [bracketed] placeholders.
- Connect the listed tools (as needed) as connectors when Grok Bot asks.
- If the task repeats, ask: "Make this a daily routine."
Alternatives: the same prompt works in Codex, Claude, ChatGPT Agent, OpenClaw.
Set it up
Stack: Codex + public Kepler/TESS data
- Read the original source for full context.
- Connect the tools your agent needs.
- Paste the prompt and replace [bracketed] placeholders.
- Run once manually and check the output before scheduling it.
Generic suggested steps, not from the source.
Evidence
First-hand Reddit post with the target star, period, size estimate and a public evidence page (kuber.studio/planethunt) showing the folded light curve and held-back data checks. Different person, star and agent from entry #60
Source: Reddit · 2026-10-18 · Verified by us: not yet · Report broken or outdated