We present spectroscopic observations of 26 galaxies of type E and S0 , based on their blue morphologies , located in voids by the study of Grogin & Geller ( 1999 ) .
Measurements of redshift , velocity dispersion , and four Lick line indices , Mg _ { b } , Fe5270 , Fe5335 , and H \beta with their errors are given for all of these galaxies , along with H \beta , [ OIII ] , H \alpha , and [ NII ] emission line strengths for a subset of these objects .
These sources are brighter than M ^ { * } for low density regions and tend to be bluer than their counterpart early-type objects in high density regions .
Using the models of Thomas et al .
( 2003 ) gives metal abundances and ages with a median \alpha enhancement , [ \alpha / Fe ] = +0.13 , and median metals abundance , [ Z / H ] = +0.22 , values comparable to those found for E and S0 galaxies in clusters , but with a wider spread in [ Z/H ] towards low values .
If the emission line subsample is interpreted as younger , the proportion of young objects is higher than for early-types in higher density regions .
There is a significant incidence of sources in the sample with emission lines in their spectra ( 46 % with H \beta and [ OIII ] and 69 % with H \alpha or [ NII ] ) as well as shells and rings in their morphologies ( 19 % ) .
The diagnostic \log [ NII ] / H \alpha , \log [ OIII ] / H \beta diagram places 10 of 12 emission line galaxies in or near the star forming and liner region and two among the Seyferts .
The H \alpha fluxes indicate star formation rates of 0.2 to 1.0 M _ { \odot } { yr ^ { -1 } } .
The percentage of these early-type void galaxies undergoing star formation appears to be higher compared to their cluster counterparts and the range of ages wider .