  We investigate the wind of lambda And, a solar-mass star that has evolved off
the main sequence becoming a sub-giant. We present spectropolarimetric
observations and use them to reconstruct the surface magnetic field of lambda
And. Although much older than our Sun, this star exhibits a stronger (reaching
up to 83 G) large-scale magnetic field, which is dominated by the poloidal
component. To investigate the wind of lambda And, we use the derived magnetic
map to simulate two stellar wind scenarios, namely a polytropic wind
(thermally-driven) and an Alfven-wave driven wind with turbulent dissipation.
From our 3D magnetohydrodynamics simulations, we calculate the wind thermal
emission and compare it to previously published radio observations and more
recent VLA observations, which we present here. These observations show a basal
sub-mJy quiescent flux level at ~5 GHz and, at epochs, a much larger flux
density (>37 mJy), likely due to radio flares. By comparing our model results
with the radio observations of lambda And, we can constrain its mass-loss rate
Mdot. There are two possible conclusions. 1) Assuming the quiescent radio
emission originates from the stellar wind, we conclude that lambda And has Mdot
~ 3e-9 Msun/yr, which agrees with the evolving mass-loss rate trend for evolved
solar-mass stars. 2) Alternatively, if the quiescent emission does not
originate from the wind, our models can only place an upper limit on mass-loss
rates, indicating that Mdot <~ 3e-9 Msun/yr.
