  We derive a self-consistent set of atmospheric parameters and abundances of
17 elements for the red giant star Arcturus: Teff = 4286+/-30 K, logg =
1.66+/-0.05, and [Fe/H] = -0.52+/-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 um). 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 FeI and 9 FeII lines, unblended in the spectra of both
Arcturus and the Sun; the [Fe/H] value adopted is derived from FeI lines. We
also determine the mass, radius, and age of Arcturus: M = 1.08+/-0.06 Msun, R =
25.4+/-0.2 Rsun, and t = 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.
