Stars observed in the FEROS programme (HR diagram)

Part of the Hertzsprung-Russell (HR) diagram - a very useful way to illustrate stellar evolution. Plotting the temperature of solar-type stars (abscissa; in degrees Kelvin or as a "colour index") against their intrinsic brightness (ordinate; in solar units) reveals a typical distribution (hotter stars are less bright than cooler stars) that reflects their different evolutionary stages. With time, the position of the Sun in this diagram (now at the lower left) will migrate towards the upper right as it expands and becomes brighter. This direction corresponds to increasing radius. The positions and names of four giant stars that are known to host planets (as of 2003) are marked. The largest and brightest of them is HD 47536, as indicated by its upper-right position, relative to the three others.