  We present observations of a chromospheric jet and growing "loop" system that
show new evidence of a fan-spine topology resulting from magnetic flux
emergence. This event, occurring in an equatorial coronal hole on 2007 February
9, was observed by the Hinode Solar Optical Telescope in the Ca II H line in
unprecedented detail. The predecessor of the jet is a bundle of fine material
threads that extend above the chromosphere and appear to rotate about the
bundle axis at ~50 km/s (period <200 s). These rotations or transverse
oscillations propagate upward at velocities up to 786 km/s. The bundle first
slowly and then rapidly swings up, with the transition occurring at the onset
of an A4.9 flare. A loop expands simultaneously in these two phases (velocity:
16-135 km/s). Near the peak of the flare, the loop appears to rupture;
simultaneous upward ejecta and mass downflows faster than free-fall appear in
one of the loop legs. The material bundle then swings back in a whiplike manner
and develops into a collimated jet, which is orientated along the inferred open
field lines with transverse oscillations continuing at slower rates. Some
material falls back along smooth streamlines, showing no more oscillations. At
low altitudes, the streamlines bifurcate at presumably a magnetic null point
and bypass an inferred dome, depicting an inverted-Y geometry. These
streamlines closely match in space the late Ca II H loop and X-ray flare loop.
These observations are consistent with the model that flux emergence in an
open-field region leads to magnetic reconnection, forming a jet and fan-spine
topology. We propose that the material bundle and collimated jet represent the
outer spine in quasi-static and eruptive stages, respectively, and the growing
loop is a 2D projection of the 3D fan surface.
