This paper presents four color narrow-band photometry of clusters A115 ( z = 0.191 ) and A2283 ( z = 0.182 ) in order to follow the star formation history of various galaxy types .
Although located at similar redshifts , the two clusters display very different fractions of blue galaxies ( i.e .
the Butcher-Oemler effect , f _ { B } = 0.13 for A115 , f _ { B } = 0.30 for A2283 ) .
A system of photometric classification is applied to the cluster members that divides the cluster population into four classes based on their recent levels of star formation .
It is shown that the blue population of each cluster is primarily composed of normal starforming ( SFR < 1 M _ { \sun } yrs ^ { -1 } ) galaxies at the high luminosity end , but with an increasing contribution from a dwarf starburst population below M _ { 5500 } = -20 .
This dwarf starburst population appears to be the same population of low mass galaxies identified in recent HST imaging ( Koo et al . 1997 ) , possible progenitors to present-day cluster dwarf ellipticals , irregulars and BCD ’ s .
Deviations in the color-magnitude relationship for the red galaxies in each cluster suggest that a population of blue S0 ’ s is evolving into present-day S0 colors at this epoch .
The radial distribution of the blue population supports the prediction of galaxy harassment mechanisms for tidally induced star formation operating on an infalling set of gas-rich galaxies .