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Hipparcos parallax measurements of stars in the Pleiades notoriously result in a cluster distance of 118 pc; ~10% shorter than the `classical results of MS-fitting. In an earlier paper we developed a purely empirical MS-fitting method to address this problem, which produced conflicting results between the (B-V) and (V-I) colour indices, indicating that the clusters photometric metallicity is substantially lower than its (~solar) spectroscopic metallicity. We were able to reconcile the discrepancy by assuming [Fe/H]=-0.4 (as indicated from (B-V)/(V-I) colour-colour plots), and the distance moduli obtained from the 2 indices were in agreement with the Hipparcos result, within the 1sig errors. With the release of the 2MASS All Sky Catalogue, we now apply our MS-fitting method to the Pleiades using the infrared colours, in order to test the plausibility of our earlier result. Fitting in the V/(V-K) and K/(J-K) colour planes, we find that assuming a subsolar metallicity does not produce distances in agreement with the (B-V) and (V-I) results. However the infrared plus (V-I) distances are in mutual agreement when adopting the spectroscopic metallicity. By considering only stars with Mv<=6, the infrared and optical colour indices all yield consistent distances using the spectroscopic [Fe/H]. The concordant distances thus obtained from the (B-V), (V-I), (V-K) and (J-K) indices yield a mean of 133.8+/-3 pc, in excellent agreement with the pre-Hipparcos MS-fitting results, and the most recent determinations from other methods. We conclude that there are two distinct issues affecting the Pleiades: the Hipparcos parallax is in error by ~10%, as previously claimed; the (B-V) colours of the lower MS are anomalous, and we caution against their use for MS-fitting to the Pleiades and similarly young open clusters. (Abridged)
We present a determination of the distance modulus of the globular cluster NGC 5904 (M 5), obtained by means of the subdwarf main-sequence fitting on the (V,V-I) color-magnitude diagram. The subdwarf sample has been selected from the HIPPARCOS catalo
The effect of atomic diffusion on the Main Sequence (MS) of metal-poor low mass stars is investigated. Since diffusion alters the stellar surface chemical abundances with respect to their initial values, one must ensure - by calibrating the initial c
Aims: We provide a new distance estimate for the Pleiades based on the moving cluster method, which will be useful to further discuss the so-called Pleiades distance controversy and compare it with the very precise parallaxes from the Gaia space miss
Extended main-sequence turn-offs (eMSTO) are a commonly observed property of young clusters. A global theoretical interpretation for the eMSTOs is still lacking, but stellar rotation is considered a necessary ingredient to explain the eMSTO. We aim t
We report the results of a near-infrared survey for long-period variables in a field of view of 20 arcmin by 30 arcmin towards the Galactic Centre (GC). We have detected 1364 variables, of which 348 are identified with those reported in Glass et al.