1 Introduction

The star-formation activity is a fundamental parameter in the study of the formation and evolution of galaxies. Being linearly related to the number of young O-B massive stars, the H$\alpha$ line emission is the most direct tracer of star formation in normal, late-type galaxies (Kennicutt 1998). In order to study the star formation history of objects of different mass, luminosity, type and belonging to different environments (cluster, field), we are gathering H$\alpha$ data for a large sample of galaxies in the nearby Universe for which data at other wavelengths are already available. We focused our attention on the closest rich cluster of galaxies, the Virgo cluster, for which H$\alpha$ data of galaxies spanning the whole range in luminosity and morphological type, from giant early spirals to dwarfs irregulars and BCDs, can be easely obtained with 2 m class telescopes.

In this paper we present new H$\alpha$ surface photometry of late-type galaxies in the Virgo cluster obtained with the 1.20 m telescope at the Observatoire de Haute Provence and with the 1.23 m telescope at Calar Alto. In a companion paper (Gavazzi et al. 2002, Paper I), we present similar observations of lower luminosity Virgo galaxies carried out with the San Pedro Martir 2.1 m telescope. In a third paper (Boselli et al. 2002, Paper III) we present H$\alpha$ observations of blue compact galaxies carried out at the INT and NOT telescopes in La Palma. The data were jointly discussed in Boselli et al. (2001), Boissier et al. (2001) and will be further discussed in a future communication (Gavazzi et al. in preparation, Paper IV).