The Little Cub: Discovery of an Extremely Metal-Poor Star-Forming Galaxy
  in the Local Universe
  We report the discovery of the Little Cub, an extremely metal-poor
star-forming galaxy in the local Universe, found in the constellation Ursa
Major (a.k.a. the Great Bear). We first identified the Little Cub as a
candidate metal-poor galaxy based on its Sloan Digital Sky Survey photometric
colors, combined with spectroscopy using the Kast spectrograph on the Shane 3-m
telescope at Lick Observatory. In this letter, we present high-quality
spectroscopic data taken with the Low Resolution Imaging Spectrometer at Keck
Observatory, which confirm the extremely metal-poor nature of this galaxy.
Based on the weak [O III] 4363 Angstrom emission line, we estimate a direct
oxygen abundance of 12 + log(O/H) = 7.13 +/- 0.08, making the Little Cub one of
the lowest metallicity star-forming galaxies currently known in the local
Universe. The Little Cub appears to be a companion of the spiral galaxy NGC
3359 and shows evidence of gas stripping. We may therefore be witnessing the
quenching of a near-pristine galaxy as it makes its first passage about a Milky
Way-like galaxy.
