The effect of gravity on the relationship between effective temperature and spectral type for O-dwarfs

27/11/2014

The relationship among effective temperature (Teff), spectral type (SpT) and metallicity of O-type stars has been extensively studied. A recent work, led by the SO Postdoc at IAC Sergio Simón-Díaz, warns about the danger of extracting conclusions about the dependence on metallicity of the SpT-Teff calibrations for small samples of O-dwarf stars. The analysis shows that the large range of gravities found for O-type dwarfs produces a significant scatter in the Teff-SpT calibrations that can hamper the investigation of metallicity effects on this type of calibrations. This was the main conclusion highlighted by Simón-Díaz and collaborators from the homogeneous analysis of the largest sample of O-dwarf stars with different metallicity studied to date, extracted from the IACOB and VFTS surveys. More information: Simón-Díaz et al. 2014, A&A 570, L6