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The chemical abundance ratios and radial velocities for two stars in therecently discovered Triangulum II faint dwarf galaxy have been determined fromhigh resolution, medium signal-to-noise ratio spectra from the Gemini-GRACESfacility. These stars have stellar parameters and metallicities similar tothose derived from their photometry and medium-resolution Ca II tripletspectra, and supports that Triangulum II has a metallicity spread consistentwith chemical evolution in a dwarf galaxy. The elemental abundances show thatboth stars have typical calcium abundances and barium upper limits for theirmetallicities, but low magnesium and sodium. This chemical compositionresembles some stars in dwarf galaxies, attributed to inhomogeneous mixing in alow star formation environment, and/or yields from only a few supernova events.One of our targets (Star40) has an enhancement in potassium, and resembles somestars in the unusual outer halo star cluster, NGC 2419. Our other target(Star46) appears to be a binary based on a change in its radial velocity (Deltav(rad) = 24.5 +/- 2.1 km/s). This is consistent with variations found in binarystars in other dwarf galaxies. While this serves as a reminder of the highbinary fraction in these ultra faint dwarf galaxies, this particular object hashad little impact on the previous determination of the velocity dispersion inTriangulum II.

Gemini/GRACES Spectroscopy of Stars in Triangulum II