Orbital Arc Detection: Long-Exposure Time-Domain Imaging for Exoplanet Direct Detection

Current exoplanet direct imaging techniques seek steady-state reflected light signals, requiring extreme contrast ratios and sophisticated wavefront control to separate planetary flux from stellar glare. This paper proposes an alternative methodology: Orbital Arc Detection (OAD), which exploits the fundamental kinematic difference between planets and optical artifacts. By employing extended exposure times scaled to orbital periods, planetary illumination events produce curved trajectories centered on the host star, while static speckles and background objects produce distinct signatures. This approach transforms the detection problem from contrast-limited photometry to motion-based pattern recognition, potentially enabling direct imaging with smaller apertures and simpler optical systems.