LMC samples. We address this possibility in the next section.

If we neglect V19 which appears anomalously blue (see Sect. \[var\_section\]), stars seem to evolve up to $K$$\approx$6.7 in the 47Tuc equivalents of sequences B and C$^{\prime}$, and to then switch to sequence C for the final stage of evolution. Using the results in Wood et al.([@wm99]), this switch seems to correspond to a transition in pulsation from a low order radial overtone mode to the fundamental radial mode (compare also Lebzelter et al.[@LWHJF05]).

The tip of the RGB in the $K$-$\log P$ diagram occurs at $K=$7.1 (see Fig.\[klp\_th\]) at log$L$/L$_{\odot}$=3.355. From Figs.\[klp\_obs\] and \[hrd\] we can say that about half of the variables are more luminous than the RGB tip and therefore must be AGB stars. The stars below the RGB tip could be either on the AGB or the RGB.

Pulsation models
================

Description of the models
-------------------------

With a substantial set of LPVs now known in 47Tuc, we are in a position to make theoretical models for the period-luminosity laws. For our models, we adopt the following parameters for 47Tuc (see the Introduction): distance modulus $(m-M)_{V}$=13.5, reddening $E(B-V)$$=$0.024, helium mass fraction Y=0.27, metal abundance Z=0.004 and main-sequence 