LOW-LUMINOSITY EARLY-TYPE GALAXIES .1. PHOTOMETRY AND MORPHOLOGY

We present new multiaperture photoelectric photometry in U, B, V, R an d I for 50 southern low-luminosity early-type galaxies (LLE). Asymptot ic magnitude and mean surface brightness within the effective aperture are derived from fits to r1/4 growth curves and colours have been red uced at the effective radius for 154 galaxies (106 LLE and 48 comparis on galaxies). A morphological and structural analysis of the LLE sampl e, based on ESO-LV image data base shows that: (i) The average flatten ing of these galaxies is high: [b/a] = 0.58. (ii) The sample can be sp lit in four main categories (plus two secondary). First, the galaxies wearing r1/4 photometric profile along the two principal axes which ha ve an average flattening of [b/a] = 0.7 (32% of the sample). Second, t he galaxies presenting r1/4 profile only along the minor axis, these g alaxies are generally flatter: [b/a] = 0.4, and show significant posit ive a4 coefficient, they probably contain a disk (21%). Third, the gal axies with irregular (''bumpy'') photometric profile which appear to b e of the latest type in our sample (t = -2) (25%). And fourth, the gal axies wearing a profile intermediate between r1/4 and exponential alon g major and minor axes (10%). (iii) There is no correlation between th e morphological type for t less-than-or-equal-to 3 and any of the stru ctural and geometrical properties investigated. (iv) Only a few galaxi es show a boxy isophote shape while a greater fraction shows disky iso photes.