Transit observations (vertical error bars) with the model that combines both transit and noise (median as a black line and 68% interval in gray), arbitrarily shifted vertically. Each transit observation is labeled with the transit epoch, the telescope, and the observing band. Each transit is centered relative to the maximum a posteriori value of the linear ephemeris derived in Sect. 4.1. Horizontal error bars show the mid-transit time offset from the linear ephemeris.