Proper Motion and Kinematics of the Ansae in NGC 7009

We have measured the proper motion (PM) and kinematics of the ansae in NGC 7009 using high-dispersion echelle spectra and archive narrowband Hubble Space Telescope images. Assuming that the ansae are moving at equal and opposite velocities from the central star, we obtain a system radial velocity of-53 plus or minus 2 km s super(-1), the eastern ansa approaching and the western ansa receding at v sub(r) = 5.3 plus or minus 1 km s super(-1) with respect to this value. The PM of the eastern ansa is 28 plus or minus 8 mas yr super(-1), which, with our weighted distance to NGC 7009 of 0.86 plus or minus 0.34 kpc, gives V sub(exp) = 114 plus or minus 32 km s super(-1). The electron temperature and density in both ansae were determined to be T sub(e) [approx] 9000 plus or minus 400 K and n sub(e) [approx] 2300 plus or minus 400 cm super(-3). The dynamic age of the ansae is [approx]910 plus or minus 260 yr, and the implied PM of the central star is mu sub(CS) = 1 plus or minus 0.5 mas yr super(-1). This is in qualitative but not quantitative agreement with previous work.