All Figures

	Figure 1: Color-magnitude diagram of the open cluster M 67. (V, B-V) photometry is taken from Montgomery et al. (1993). The location of the Li-rich subgiant star (S1242) is indicated in this diagram.
Open with DEXTER


In the text

	Figure 2: Spectroscopic observation of S1242 (dotted line) in the H line region. Synthetic spectra have been computed at effective temperature of 5700 K (dashed-dot line), 5800 K (solid line) and 5900 K (long-dashed line). For S1242, we have adopted  K.
Open with DEXTER


In the text

	Figure 3: a) Lithium line region of S1242 (dotted line) and synthetic spectra computed with the atmospheric parameters listed in Table 2, and with , 2.7 and 2.8 dex (dashed, solid and dashed-dot lines respectively). The best synthetic spectrum is clearly the one computed with . b) Residual difference between synthetic ( , best fit) and observed spectra.
Open with DEXTER


In the text

Figure 4:   evolution for three stellar models of 1.33 . The reader is referred to Michaud et al. (2004) for a full description of the models. The dotted line is the initial  , set at 3.0 dex at the beginning of the main sequence, as no Li destruction on the pre-Main Sequence has been considered. The three different curves correspond to different models, taking into account atomic diffusion (solid line) and two different parametrizations of the mixing (dashed and dot-dashed lines, see text). Black dots represent the surface Li abundances predicted by our models from 3.6 to 3.8 Gyr (i.e., the expected age for M 67).

Open with DEXTER


In the text