NASA’s TESS has an active Director’s Discretionary Target program, number 100, for TIC 4206066, a late-K dwarf. The program is scheduled to observe the star at a two-minute cadence from Oct. 31 through Nov. 26, 2026, testing two transit-like candidate signals reported by independent researcher Pavel Rabtsevich. He describes them as candidate signals; his analysis does not claim statistical validation.
What the two signals show
Rabtsevich reports a stronger pattern in TESS Sectors 6, 32, and 98, with a 3.18-day period and brightness dips of about 500 parts per million. If a planet orbiting TIC 4206066 causes those dips, the estimated radius would be 1.4 ± 0.1 Earth radii.
The second signal is weaker and tentative. Its reported period is 11.13 days, and its estimated radius would be about 2.2 Earth radii if it, too, came from a planet orbiting the star. Rabtsevich reports roughly 3σ significance for this signal in a post-hoc test—a check conducted after the signal surfaced.
| Signal | Reported period | Estimated radius if orbiting TIC 4206066 |
| Stronger candidate | 3.18 days | 1.4 ± 0.1 Earth radii |
| Weaker, tentative candidate | 11.13 days | About 2.2 Earth radii |
A transit-like signal is a dip in a star’s brightness consistent with an object passing in front of it. That pattern can point to a planet, but it does not identify the object by itself.
What the scheduled TESS observations will test
The protocol for the upcoming Sector 110 observations predicts nine transits for the stronger signal and three for the weaker one. It sets predicted timings, data processing, and outcome categories in advance; the timing uncertainty is about four minutes at one standard deviation.
A repeat of a predicted dip would provide another test of the candidate signals. Rabtsevich’s protocol says that recovering a signal alone would not prove a planet caused it.
How Claude Code figured into the analysis
Rabtsevich says Claude Code assisted with parts of the work, including data handling, search code, transit fitting, and false-positive checks. He says he chose the questions and pass/fail criteria. He also reports using Opus 5.5 and Fable 5.1.
