SIMBAD references

Data for 405 contact binary systems extracted from a recent compilation are supplemented by information from the literature for an additional ten ultrashort period (P < 0.2 d) binaries. This is used to calibrate period-luminosity-temperature relations for contact binaries. The derived relations are applied to a standard mean temperature-luminosity tabulation to obtain predicted periods for contact systems over the spectral range M9.5-A2. Minimum periods in the range 0.08-0.15 d follow, depending on the precise period-luminosity-temperature model fitted.