Color–magnitude diagram of SAGB stars. The adopted progenitor models (filled circles; colors are the same as in Figure  1) are compared with evolutionary models of SAGB stars with various M _MS (lines: M _MS = 8.8  M _☉ (red), 9  M _☉ (green), 9.5  M _☉ (blue), 10  M _☉ (magenta), and 10.5  M _☉ (cyan), Siess 2007) and the luminosity range of the progenitor of SN 2008S (shaded gray region; Prieto et al. 2008; Botticella et al. 2009). L _☉ is the solar luminosity.