The terms Reference star, Check star and Comparison star refer to different types of stars used for specific purposes during the Phoranso photometric analysis.


A comparison star serves a similar purpose to a check star, with one notable distinction: it is not included in AAVSO reports. 


Phoranso allows to work with zero or more comparison stars (>=0) and uses the convention to color an Aperture Ringset around a check star in orange.