We derive a self-consistent set of atmospheric parameters and abundances of 17 elements for the red giant star Arcturus : T _ { \mathrm { eff } } = 4286 \pm 30 K , \log g = 1.66 \pm 0.05 , and \mathrm { [ Fe / H ] } = -0.52 \pm 0.04 .
The effective temperature was determined using model atmosphere fits to the observed spectral energy distribution from the blue to the mid-infrared ( 0.44 to 10 \mu m ) .
The surface gravity was calculated using the trigonometric parallax of the star and stellar evolution models .
A differential abundance analysis relative to the solar spectrum allowed us to derive iron abundances from equivalent width measurements of 37 Fe i and 9 Fe ii lines , unblended in the spectra of both Arcturus and the Sun ; the \mathrm { [ Fe / H ] } value adopted is derived from Fe i lines .
We also determine the mass , radius , and age of Arcturus : M = 1.08 \pm 0.06 M _ { \odot } , R = 25.4 \pm 0.2 R _ { \odot } , and \tau = 7.1 ^ { +1.5 } _ { -1.2 } Gyr .
Finally , abundances of the following elements are measured from an equivalent width analysis of atomic features : C , O , Na , Mg , Al , Si , K , Ca , Sc , Ti , V , Cr , Mn , Co , Ni , and Zn .
We find the chemical composition of Arcturus typical of that of a local thick-disk star , consistent with its kinematics .