TITLE: GCN CIRCULAR NUMBER: 16774 SUBJECT: GRB 140903A: tentative spectroscopic redshift DATE: 14/09/04 14:30:39 GMT FROM: Antonino Cucchiara at NASA/GSFC A. Cucchiara (NASA-GSFC), S.B. Cenko (NASA-GSFC), D. A. Perley (Caltech), J. Capone (UMD), and V. Toy (UMD) report on behalf of a larger collaboration: On September 4.20 UT we observe the candidate afterglow of the short GRB 140903A (Cummings et al. GCN 16763, Kennea et al. GCN 16764, Capone et al. GCN 16769) with the Gemini-North telescope equipped with the GMOS camera. A set of 2x600s exposures were obtained in spectroscopic mode: our spectra covered the wavelength range 4000-8100 Angstroms at a resolution of R~1200. We clearly identify a strong absorption doublet feature at the observed wavelength 7954, 7965 Angstrom and a weak emission line at 6570 Angstrom. We tentatively interpret these features as NaID in absorption and H-beta line in emission at the common redshift of z=0.351. No other clear features are visible neither in emission nor in absorption, therefore we suggest this to be the redshift of the host galaxy of GRB 140903A. We thank the Gemini staff, in particular Jess Ball, for their prompt assistance with these observations.