The luminosity function of the globular cluster NGC 6752 with the Hubble Space Telescope: Evidence of mass segregation

We present the luminosity function (LF) for the lower main sequence of the Galactic globular cluster NGC 6752, as obtained from Hobble Space Telescope (HST) observations centred 2 arcmin from the cluster centre. We present data in the F814W and F555W filters. Our LF reaches down to M-I= 11 or, translated to a mass function, to M similar or equal to 0.12 M.. The LF reaches a maximum between M-I = 8.5 and 9, and shows no indication of an increase towards lower luminosities/masses; this is at variance with some ground-based observations, but is similar to all other HST-based LFs. There is a clear indication of mass segregation since the relative numbers of bright/faint stars differ from that found in ground-based observations and in other clusters analysed with the HST.