Asymmetric fits to 104 GX 301-2 orbits in 2010-2022 give different rise and decay lags at 4-10 and 15-50 keV

We test whether one time shift can align the soft and hard mean X-ray flares of GX 301-2. We reuse public BAT and MAXI data and 104 selected orbits in 2010-2022. Each available orbit mean has equal weight in each phase bin. Asymmetric Lorentzian fits give a BAT 15-50 keV lag behind MAXI 4-10 keV of 1.59 days at the rise half-height crossing. The decay lag is 0.28 day. The soft-band full width at half maximum exceeds the hard-band width by 1.31 days. The paired orbit-bootstrap 95% interval is 0.54 to 2.21 days. Any single shift must leave at least one fitted edge in error by 0.66 day. Its interval is 0.27 to 1.10 days. Within MAXI, the 4-10 keV profile is 1.32 days wider than the 10-20 keV profile. Its interval is 0.62 to 2.15 days. Gaussian fits and other controls give positive fitted width differences. The size depends on the shape and baseline. Direct smoothed crossings give 0.73 day with interval -0.06 to 1.39 days. Data after the camera change and from later years give weaker constraints. Simulations at the real observing times show little width bias under two stated noise models. This study quantifies known energy-dependent structure and tests a correction with one time shift. It does not identify a physical cause or measure orbital decay. The package preserves data provenance, code, profiles, fit and resample arrays, figures, and offline instructions.

GX 301-2 · X-ray binaries · flare timing · energy-dependent profiles · Swift BAT · MAXI · orbital phase · reproducible astronomy