We have obtained multi-object spectroscopy of luminous blue supergiants in NGC 3109 , a galaxy at the periphery of the Local Group at \sim 1.3 Mpc .
We present a detailed catalog including finding charts , V and I magnitudes , spectral classifications , and stellar radial velocities .
The radial velocities are seen to trace the rotation curves obtained from studies of the H I gas .
From quantitative analysis of eight B-type supergiants we find a mean oxygen abundance of 12 + log ( O/H ) = 7.76 \pm 0.07 ( 1-sigma systematic uncertainty ) , with a median result of 7.8 .
Given its distance , we highlight NGC 3109 as the ideal example of a low metallicity , dark-matter dominated , dwarf galaxy for observations with the next generation of ground-based extremely large telescopes ( ELTs ) .