Subject: abstract of the talk

From: [email-masked] (Giampaolo Piotto (Padova) - Tel. 049-8293483)
Date: Thu, 27 Jul 1995 17:20:16 +0200

STELLAR LUMINOSITY AND MASS FUNCTIONS OF GLOBULAR CLUSTERS
Giampaolo Piotto

				ABSTRACT

I will present a brief historical review on the last ten year research in the 
field of Galactic Globular Cluster (GC) luminosity functions (LFs) and 
mass functions (MFs).

The talk will then be focussed on our recently obtained LFs from deep
HST data, which allow for the first time to span the entire mass range
of the main sequence stars, from the turn--off almost down to the
theretical limit for the core-hydrogen burning ignition (i.e. about
0.1 solar masses).

A comparison of the HST LFs for 5 GCs (47Tuc, Omega Cen, NGC 6397, NGC 7078, 
and NGC 7099) shows remarkable similarities and significant differences.
The possible explanations and implications of these results will be discussed. 

The uncertainties of the mass luminosity relations presently available and the
limitation that they pose on the interpretation of our LFs will be briefly 
presented.
It will also be shown that the MFs extracted from our HST LFs using the most 
recently calculated mass-luminosity  relations do not present any sign of 
flattening or drop off at the faint end. Instead, a power law can well 
represent their trend below 0.4 solar masses, though with a much shallower 
slope than previously proposed.