Can Kepler See Faculae?

We investigate how faculae are manifested in the precision broad-band light curves gathered by
Kepler from solar-type stars. We show the purely facular signal could easily reveal their
rotation periods, but for stars like the Sun the accuracy of the inferred period from observations
is kept low by short-lived starspots. We find that faculae would have to be twice as bright to
overcome this problem. One way to increase the influence of real faculae is to use bluer
bandpasses. Otherwise faculae do not affect broad-band differential light curves in a
measurable way, and so are probably not explanatory of other effects found in Kepler light
curves. This is even more true for TESS differential light curves