Low Metallicity Indicates That the Hypervelocity Star HE 0437-5439 was Ejected from the Large Magellanic Cloud

We measure the metallicity of the unusual hypervelocity star HE 0437–5439 from high-resolution spectroscopy to be half-solar. We determine a spectral type of B2 IV-III for the star and derive an effective temperature T eff = 21,500 ± 1000 K and a surface gravity log g = 3.7 ± 0.2 (cgs). We also pres... View More