The sample of 693 stars plotted in Galactic coordinates. Intrinsically bright stars with M_V < − 2 mag (which are also located farther than 1 kpc) are marked by red open circles and stars intrinsically fainter than − 2 mag (which are all found closer than 1 kpc) by black filled circles. Stars from the classical Cen OB1 association are marked by blue ×-symbols. The stars from the Luminous Stars catalog (Reed 2003) are represented by green vertical symbols. The concentrations represent NGC 4755 (l,b = 303206, 259) and St 16 (l,b = 30615, 00656). See details in Sect. 3. See the electronic edition for a color version of the figure.