We assemble a sample of 17 low-metallicity (7.45<log(O/H)+12<8.12) galaxies with z<=0.1 found spectroscopically, without photometric preselection, in early data from the Hobby-Eberly Telescope Dark Energy Experiment. Star-forming galaxies that occupy the lowest-mass and lowest-metallicity end of the mass-metallicity relation tend to be undersampled in continuum-based surveys as their spectra are typically dominated by emission from newly forming stars. We search for galaxies with high [OIII]{lambda}5007/[OII]{lambda}3727, implying highly ionized nebular emission often indicative of low-metallicity systems. With the Second Generation Low Resolution Spectrograph on the Hobby-Eberly Telescope we acquired follow-up spectra, with higher resolution and broader wavelength coverage, of each low-metallicity candidate in order to confirm the redshift, measure the H{alpha} and [NII] line strengths, and, in many cases, obtain deeper spectra of the blue lines. We find our galaxies are consistent with the mass-metallicity relation of typical low-mass galaxies. However, galaxies in our sample tend to have similar specific star formation rates as the incredibly rare "blueberry" galaxies found by Yang+ (2017, J/ApJ/847/38). We illustrate the power of spectroscopic surveys for finding low-mass and low-metallicity galaxies and reveal that we find a sample of galaxies that are a hybrid between the properties of typical dwarf galaxies and the more extreme blueberry galaxies.

Cone search capability for table J/ApJ/916/11/table1 (*Basic properties of objects in the sample)