In the study of light curves, there will be times where you are able to capture an entire period of variability in the course of one sitting/measurement. However, the reality is that this will not be the case. Examples include: Sun position, Sun rise, weather, equipment, length of variability period, etc. Phase plots, through folding data, provide a way for us to discover a light curve from multiple measurements.
Light Curve O-C Diagrams
The O–C (Observed – Computed) method is the classical method for studying period changes in variable stars, because it is sensitive to the cumulative effect of the period changes. O-C diagrams compare the observed time of maximum brightness O with the calculated time...