We present the SAO 6 m telescope spectroscopy of a blue compact galaxy ( BCG ) HS 2134+0400 discovered in frame of the dedicated Hamburg/SAO survey for Low Metallicity BCGs ( HSS-LM ) .
Its very low abundance of oxygen ( 12+ \log ( O/H ) = 7.44 ) , as well as other heavy elements ( S , N , Ne , Ar ) , assigns this dwarf galaxy to the group of BCGs with the lowest metal content .
There are only eight that low metallicity among several thousand known BCGs in the nearby Universe .
The abundance ratios for the heavy elements ( S/O , Ne/O , N/O , and Ar/O ) are well consistent with the typical values of other very metal-poor BCGs .
The global environment of HS 2134+0400 is atypical of the majority of BCGs .
The object falls within the Pegasus void , the large volume with the very low density of galaxies with the normal ( M _ { B } ^ { * } =–19.6 ) or high luminosity .
Since we found in voids a dozen more the very metal-poor galaxies , we discuss the hypothesis that such objects can be representative of a substantial fraction of the void dwarf galaxy population .