We present V and I photometry for a field 5' from the center of 47 Tuc. The field was imaged with the HST WFPC2 as part of the Medium Deep Survey project. The luminosity function (LF) continually rises in the domain $5 0.4 M_\odot$, the 47 Tuc mass function is significantly different from that of \wcen. The calibrated HST $M_V(V-I)$ colour-magnitude diagrams (CMDs) show a trend with metallicity in the sense of metal richer systems having redder CMDs for a fixed absolute magnitude. The main-sequence becomes shallower with increasing metallicity. For metal-rich systems, the CMDs derived from HST are in general agreement with previous ground-based studies. However, the CMDs of metal poor subdwarfs observed from the ground are shallower than those of globular clusters observed with HST.
[1]
Georges Meylan,et al.
Structure and dynamics of globular clusters
,
1993
.
[2]
A. Philip,et al.
IAU Colloquium No. 76, The Nearby Stars and the Stellar Luminosity Function
,
1982
.
[3]
S. Majewski.
Galaxy evolution : the Milky Way perspective : proceedings of a seminer series held at the Observatories of the Carnegie Institution of Washington, Hale Library, Santa Barbara Street, Pasadena, California, in the Winter and the Spring of 1992
,
1993
.
[4]
C. Tinney.
The Bottom of the Main Sequence — And Beyond
,
1995
.
[5]
C. Payne-Gaposchkin.
Globular Clusters
,
1979,
Nature.