A moon-deep transit with a planet-mass dynamical companion admits a short list of mundane explanations. Each one breaks on an observable that the genuine dark-primary configuration does not — one of them inside the detection pipeline itself, the rest with standard follow-up.
Code
from lastmoon.vetting import vetting_tablevetting_table()
Table length=5
scenario
mimics
tier
discriminant
rejection
str38
str60
str9
str145
str250
White-dwarf companion
a dark, massive primary paired with a small transiting body
follow-up
a WD is luminous (UV/optical excess in the SED), and a transiting WD's depth-derived radius is Earth-scale (~6e6 m), not lunar
no UV excess and a depth-derived radius consistent with a lunar-size body
Iron/ultra-dense dark planet
a high-density transiting object with a large dynamical mass
pipeline
even a pure-iron world obeys a mass-radius relation; the dynamical mass implied at the transiting radius exceeds any condensed-matter composition
mass_size_mismatch > 3 (the live pipeline threshold) is unreachable for iron-world compositions
Blended eclipsing binary
a shallow moon-depth transit from a diluted deep eclipse
follow-up
centroid shift during events; chromatic depth; secondary eclipses
achromatic depth, no centroid motion, no secondary eclipses
Grazing stellar eclipse
a shallow transit from a stellar companion clipping the limb
box-consistent shape and an RV amplitude at the m/s scale
Ordinary planet with a transiting moon
moon-only transits with planet-scale dynamical mass
follow-up
a non-transiting planet can host a transiting moon, so a planet transit is not guaranteed
no planet-depth event in the primary-transit windows predicted by the joint RV + moon-timing geometry, when that geometry requires one; otherwise this remains a residual false positive requiring extended follow-up — not closed by the current pipeline
The pipeline-tier rejection regenerates from the package on every build, so the threshold shown always matches the survey configuration. The residual case — an ordinary non-transiting planet whose moon transits — is the honest hard one: it is only closed when the joint RV + moon-timing geometry predicts a planet transit that fails to appear.