Science background

Active stellar surfaces can reshape exoplanet timing measurements.

Transit mid-time measurements are used to track ephemerides, search for additional planets, and test orbital evolution. In active stars, dark spots and bright faculae can perturb the shape of the transit and shift the apparent timing signal.

Why this matters

A planet crossing a spotted stellar surface does not produce a perfectly symmetric light curve. If that distortion is ignored, a timing fit can move the transit center to compensate. The resulting apparent T0 offset can be comparable to the timing precision used in ephemeris and TTV studies.

Research questions

Which stellar, planetary, and spot parameters produce the largest timing bias?
When can a contaminated transit be physically corrected?
When is uncertainty inflation more defensible than correction?
Which active systems provide the strongest real-data validation cases?

Method concept

The project combines forward simulations, physical transit-plus-spot models, machine-learning detection, Bayesian posterior checks, and archive-data validation. Machine learning is used as a triage and detection component; the timing correction remains tied to interpretable physical modelling.

Validation roster

Named candidate systems for the 10-12 target core.

HAT-P-11b Kepler active-star benchmark with visible spot-crossing morphology

WASP-19b TESS hot-Jupiter case for injection-recovery experiments

HAT-P-36b Hard case where method sensitivity and activity remain explicit

WASP-52b Active host with TESS and JWST relevance

Kepler-17b High-activity comparison system for domain-gap testing

HD 189733b Bright active hot-Jupiter benchmark with public TESS products

Qatar-1b High-cadence TESS candidate for multi-epoch timing checks

WASP-4b Timing-benchmark system for orbital-decay/TTV confusion tests

WASP-12b Orbital-decay benchmark and false-positive control case

AU Mic b Young active M-dwarf stress test for robust triage

WASP-43b Short-period hot-Jupiter benchmark with public TESS coverage

K2-25b Young K2 system for activity-sensitive validation