  Very high resolution (R~160,000-210,000), high signal-to-noise ratio
(S/N>300) spectra of nine bright K-dwarfs were obtained with the 2dcoude
spectrograph on the 2.7m Telescope at McDonald Observatory to determine
wavelength shifts and asymmetries of Fe I lines. The observed shapes and
positions of Fe I lines reveal asymmetries and wavelength shifts that indicate
the presence of granulation. In particular, line bisectors show characteristic
C-shapes while line core wavelengths are blueshifted by an amount that
increases with decreasing equivalent width (EW). On average, Fe I line
bisectors have a span that ranges from nearly 0 for the weakest lines (residual
core flux > 0.7) to about 75 m/s for the strongest lines (residual core flux ~
0.3) while wavelength shifts range from about -150 m/s in the weakest (EW ~ 10
mA) lines to 0 in the strongest (EW > 100 mA) features. A more detailed
inspection of the bisectors and wavelength shifts reveals star-to-star
differences that are likely associated with differences in stellar parameters,
projected rotational velocity, and stellar activity. For the inactive, slow
projected rotational velocity stars, we detect, unequivocally, a plateau in the
line-shifts at large EW values (EW > 100 mA), a behavior that had been
identified before only in the solar spectrum. The detection of this plateau
allows us to determine the zero point of the convective blueshifts, which is
useful to determine absolute radial velocities. Thus, we are able to measure
such velocities with a mean uncertainty of about 60 m/s.
