We study star formation in a sample of 345 galaxies in 167 pairs and compact groups drawn from the original CfA2 Redshift Survey and from a follow-up search for companions .
We construct our sample with attention to including pairs with luminosity contrast \left| \Delta m _ { R } \right| \geq 2 .
These 57 galaxies with \left| \Delta m _ { R } \right| \geq 2 provide a set of nearby representative cases of minor interactions , a central feature of the hierarchical galaxy formation model .
Here we report the redshifts and positions of the 345 galaxies in our sample , and of 136 galaxies in apparent pairs that are superpositions .
In the pairs sample as a whole , there are strong correlations between the equivalent width of the H \alpha emission line and the projected spatial and line-of-sight velocity separation of the pair .
For pairs of small luminosity contrast , \left| \Delta m _ { R } \right| < 2 , the member galaxies show a correlation between the equivalent width of H \alpha and the projected spatial separation of the pair .
However , for pairs with large luminosity contrast , \left| \Delta m _ { R } \right| \geq 2 , we detect no correlation between the equivalent width of H \alpha and the projected spatial separation .
The relative luminosity of the companion galaxy is more important in a gravitational tidal interaction than the intrinsic luminosity of the galaxy .
Central star formation across the entire pairs sample depends strongly on the luminosity ratio , \left| \Delta m _ { R } \right| , a reasonable proxy for the mass ratio of the pair ; pairs composed of similarly luminous galaxies produce the strongest bursts of star formation .
Pairs with \left| \Delta m _ { R } \right| \geq 2 rarely have EW ( H \alpha ) \gtrsim 70 Å .