  We have obtained $H_{\alpha}$ fluxes and luminosities for a sample of 95
accordant galaxies from observations of 31 Hickson Compact Groups (HCGs) in the
North hemisphere. This sample is the largest $H_{\alpha}$ selected catalogue of
galaxies having $H_{\alpha}$ calibrated fluxes so far. The results obtained
from a preliminary analysis of a subsample of 66 galaxies show that the
$H_{\alpha}$ luminosity of galaxies is correlated with velocity dispersion and
compactness of groups. Such correlations would point toward a scenario in which
$H_{\alpha}$ brightest galaxies reside in compact groups having higher
probability of galaxy interaction i.e. lower values of velocity dispersion.
Moreover such relations seem to depend on the environment in which HCGs
themselves are embedded.
