The Mass Function of NGC 288

We present NICMOS NIC3 observations of the Galactic globular cluster NGC288, taken South East at 2.4 times the cluster’s half-light radius in the J and H bands. We have detected the cluster main sequence down to J ≃ 25 and H ≃ 24. The corresponding luminosity function covers the range 3 < MH < 9 and peaks at MH ≃ 6.8. The theoretical tracks of Baraffe et al. (1997) at [Fe/H ] = −1.3 give a mass function which is best fitted by a log-normal distribution with characteristic mass of mc = 0.42M⊙ and a standard deviation σ = 0.35. This result is fully consistent with the global mass function derived by Paresce & De Marchi (2000) for a sample of 12 globular clusters with very different dynamical histories, thus confirming that near the cluster’s half-light radius the mass function appears “undistorted” by evaporation or tidal interactions with the Galaxy and should then reflect the initial mass function.