![Artist’s impression of the hypergiant star HR 8752 traversing the Yellow Evolutionary Void (YEV). The image shows the increase in temperature undergone by the surface of the star in recent decades.. /© A.Lobel-ROB. SRON. Artist’s impression of the hypergiant star HR 8752 traversing the Yellow Evolutionary Void (YEV). The image shows the increase in temperature undergone by the surface of the star in recent decades.. /© A.Lobel-ROB. SRON.](/sites/default/files/styles/crop_square_2_2_to_320px/public/images/news/resultados103_108.jpg?itok=n2ttKRuS)
Context. We study the time history of the yellow hypergiant HR 8752 based on high-resolution spectra (1973-2005), the observed MK spectral classification data, B - V- and V-observations (1918-1996) and yet earlier V-observations (1840-1918). Aims: Our local thermal equilibrium analysis of the spectra yields accurate values of the effective temperature (T eff), the acceleration of gravity (g), and the turbulent velocity (v t) for 26 spectra. The standard deviations average are 82 K for T eff, 0.23 for log g, and 1.1 km s -1 for v t. Methods: A comparison of B - V observations, MK spectral
Advertised on