[astro-ph.EP] Finding planets beyond the Solar System is now largely a data-analysis problem: photometric surveys return far more stellar light curves than can be inspected by eye, and machine learning is increasingly asked to recognise the faint, periodic dimming of a transiting planet.
Whether such a detector works turns on a choice that is seldom reported: how its training labels were made. No catalogue disposes the individual measurements a per-cadence detector must classify, so the annotation has to be derived, and this paper asks what that costs.
We present Astro-Hunters, an end-to-end pipeline over TESS two-minute photometry: retrieval, detrending, seven sliding-window statistics per cadence, and gradient-boosted classification. These components are deliberately conventional.
What is new is the treatment of label provenance as an experimental variable, a corpus of 189,279 cadences from twelve confirmed hosts annotated from published ephemerides rather than from the photometry, and a physical bound on what the task permits.
Six classifier families are compared under a star-disjoint protocol. Holding features, model and protocol fixed, precision–recall performance spans a factor of 29 across label sources against 1.8 across architectures.
Labels from an isolation forest fitted to the classifier’s own features give an apparent AUC of 0.9915 that measures circularity; an unconverted transit epoch drives performance to chance; correct annotation gives AUC 0.788 at 5.3 times the prevalence baseline.
The ceiling is observational, not architectural: a median single-cadence signal-to-noise ratio of 2.10 caps per-cadence AUC at 0.932. A Box Least Squares baseline recovers eight of twelve orbital periods from one sector. Phase-folding, not classifier capacity, is what makes the transit signal accessible.
Fatimah Emad Eldin
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2608.18172 [astro-ph.EP] (or arXiv:2608.18172v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2608.18172
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Submission history
From: Fatimah Emad Eldin
[v1] Mon, 17 Aug 2026 18:41:30 UTC (205 KB)
https://arxiv.org/abs/2608.18172
Astrobiology, Astronomy, Exoplanet,
