Light curves of HD 278236. The top panel displays the composite LC of the system. Bottom left and right panels provide zoomed views of the primary and secondary eclipses, respectively. Observations from Sectors 19 to 73 span 1500 days. In the earliest sector (17) the eclipse exhibits a flat profile, indicative of a total eclipse. Over time the eclipse profile gradually smoothens, completely losing its flatness by the latest observed sector (73), indicative of a shift to a partial eclipse. Apsidal motion is also evident in this system, as demonstrated by the phase shift of the secondary eclipse.