Title:Comparing galaxy population in compact groups and loose groups galaxies: 
brightest group galaxies 

Abstract:
We study the properties of the brightest galaxies (BCGs) in compact (CGs) and 
loose groups (LGs) of galaxies to deepen our understanding of the physical 
mechanisms acting upon galaxy evolution in different environments. We select 
samples of BCGs in CGs identified by McConnachie et al., and in LGs taken from 
Zandivarez & Martínez. We compare a number of physical properties of the BCGs 
in CGs and in subsamples of LGs defined by their mass and total luminosity. We 
find that the BCGs in CGs and LGs are different. Some mechanisms responsible of 
transforming late type galaxies into early types, such as mergers, could be 
more effective within CGs due to their high densities and small velocity 
dispersion, thus leading their BCGs along somewhat different evolutionary 
paths.