Values of the stellar effective temperature and mass of the companion for systems containing a companion in the planet, brown dwarf, or M-dwarf mass range. Transiting/eclipsing systems are shown by circles, and systems only detected in radial velocimetry are shown by trianges (in which case the mass value corresponds to the mass times the sine of the inclination of the orbit with respect to the observer). The size (area) of the symbols is inversely proportional to the orbital period (see labels). The metallicity of the parent star is shown by the symbol color (see labels). Some objects deemed important for understanding the link between these parameters are labeled. The error bars on the masses are small (~10%) and would be barely visible in this diagram. The error bars on the effective temperatures are believed to range from  ~100 K to up to  ~300 K (for example for the faint OGLE-TR-122).