Zoom on NOAA 11589 at 15:00 UT on 2012 October 16, observed with SDO/AIA at 171 Å  and overplotted with selected magnetic field lines from the extrapolation (α = 7 × 10^-3 Mm^-1). Blue/green lines are magnetic field lines that give a good/poor match with the AR’s coronal loops. Solid purple/cyan lines display isocontours of the photospheric magnetic field, B_z = [ 30,100,300,1000 ] Gauss. The white arrow indicates the northern direction.