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[11.06] Proper Motion and Kinematics of the ansae in NGC 7009

R. Fernandez (CTIO PIA/REU Student - PUC), H. E. Schwarz, H. Monteiro (Cerro Tololo Inter-American Observatory)

We have measured the proper motion (PM) and kinematics of the ansae in NGC 7009 using high dispersion echelle spectra and archive narrow band HST images. Assuming that the ansae are moving at equal and opposite velocities from the central star we obtain a system radial velocity of -53 ±2 km.s^-1, the eastern ansa approaching and the western ansa receding at v_r = 5.4 ±1 km.s^-1 with respect to this value. The PM of the eastern ansa is 28 ±8 mas.yr^-1, which with our weighted distance to NGC 7009 of 0.86±0.34 kpc gives V_exp=112 ±32 km.s^-1. The electron temperature and density in both ansae were determined to be T_e ~9000 ±400 K and n_e ~2300 ±400 cm^-3. The dynamic age of the ansae is ~925 ±260 yrs. and the PM of the central star is \mu_CS = 1 ±0.5 mas.yr^-1. This is in qualitative but not quantitative agreement with previous work. This project was made as part of the 2003 PIA/REU Program in Cerro Tololo Inter-American Observatory.

The author(s) of this abstract have provided an email address for comments about the abstract: rafernan@puc.cl

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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.