; B, V, g$^{\prime}$, r$^{\prime}$ and i$^{\prime}$ magnitudes from data release 9 of the AAVSO Photometric All Sky Survey [APASS9, @2016yCat.2336....0H]; J, H and K$_{\rm s}$ magnitudes from the Two-micron All Sky Survey [2MASS, @2006AJ....131.1163S]; i$^{\prime}$, J and K magnitudes from the Deep Near-infrared Southern Sky Survey [DENIS, @2005yCat.2263....0T]. Not all stars have data in all these catalogues. Photometry from the Sloan digital sky survey (SDSS) can be unreliable for these bright stars because they saturate the detectors, but we have used g$^{\prime}$-, r$^{\prime}$- and i$^{\prime}$-band “psfMag” magnitudes from data release 9 of the SDSS [@2012ApJS..203...21A] in some cases, as noted in Table \[TeffTable\]. Magnitudes from the APASS9 catalogue that are given with a standard error estimate of 0.00 were not included in our analysis.

Our model for the observed photometry then has the following free parameters that are determined by a least-squares fit to the observed apparent magnitudes and other data for each system – g$^{\prime}_{0, i}$, the apparent g$^{\prime}$-band magnitudes for stars $i=1$, $i=2$ and (for triple systems) $i=3$, corrected for extinction; $T_{\rm eff,i}$ the effective temperatures for each star in the binary or triple system; E$({\rm B}-{\rm
V})$, the reddening to the system; $\sigma_{\rm ext}$ the additional 