Light curves of R 40 and R 110. Squares indicate OPD/LNA (this work); diamonds indicate LTPV; crosses indicate ASAS; downward triangles indicate AAVSO (V); stars indicate van Genderen (1998); circles indicate references cited in Table 3; and upward triangles indicate the median of the AAVSO (Vis.) data of each year with standard deviation error bars. The vertical lines represent the observation dates of the spectra listed in Table 1.