---
author:
- 'T. Lebzelter'
- 'P.R. Wood'
date: 'Received ; accepted '
title: 'Long period variables in 47Tuc: direct evidence for lost mass'
---

Introduction
============

It is now well established that pulsating red giant stars lie on a series of up to six parallel period-luminosity (PL) sequences (e.g. Wood et al. [@wm99], Wood [@wood00]; Ita et al. [@ita04]; Soszyński et al. [@sos04]; Fraser et al. [@fra05]). The stars known to populate these sequences are generally field variables so that their metallicities, masses and ages are not known individually, although the luminosities are well known because the stars lie in stellar systems at a known distance, such as the SMC and LMC. The dispersion in the PL relations is much larger than the amplitude of the pulsation, especially for the small amplitude variables, and this dispersion is almost certainly a consequence of the dispersion in mass and metallicity at a given pulsation period.

Comparison of the PL relations with theory (Wood et al. [@wm99]) shows that four of the PL sequences (sequences A, B and C of Wood et al. [@wm99], or sequences A, B, C and C$^{\prime}$ of Ita et al. [@ita04]) can be broadly explained by radial 