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The 3D velocity structure of the planetary nebula NGC 7009
Steffen, W.; Koning, N.; Espíndola, M. +1 more
In search for deviations from homologous expansion in planetary nebulae we present a 3D morphokinematical model of NGC 7009. The model has been constructed with Shape based on PV diagrams from the literature and HST images. We find that the data are consistent with a radial velocity field with increased gradient at high latitudes compared to the e…
Radio Proper Motions of Wolf-Rayet Stars
Rodríguez, L. F.; Dzib, S.
We present the analysis of observations taken from the Very Large Array archive of six Wolf-Rayet stars with radio emission, with the purpose of determining their proper motions. Typically, these observations cover periods of 10 to 20 years. To verify the method, we included WR 140 in the sample, and found that the proper motions determined by us …
Kinematics and Velocity Ellipsoid of the K Giants
Branham, R. L., Jr.
To study the kinematics of the K giant stars (luminosity class III) use is made of proper motions taken from van Leeuwen's new reduction of the Hipparcos catalog. 11,372 stars, of which 880 have radial velocities, were used in the final study. Semi-definite programming solves for the kinematical parameters such as the Oort constants and simultaneo…