Aberration in proper motions

Structure of proper motions in a sunspot penumbra

Proper Motions in Compact Symmetric Objects

We discuss recent measurements of proper motions of the hotspots of Compact Symmetric Objects. Source expansion has been detected in ten CSOs so far and all these objects are very young (≤ 3 × 10 3 years). In a few sources ages have also been estimated from energy supply and spectral ageing arguments and these estimates are comparable. This argues that these sources are close to equiparti-tion ...

Proper Motions in the Andromeda Subgroup

This article presents results of VLBI observations of regions of H2O maser activity in the Local Group galaxies M33 and IC 10. Since all position measurements were made relative to extragalactic background sources, the proper motions of the two galaxies could be measured. For M33, this provides this galaxy’s three dimensional velocity, showing that this galaxy is moving with a velocity of 190 ±...

Proper Motions of Ansae in Ngc

Para la nebulosa planetaria NGC 7009, presentamos una comparación de dos conjuntos de datos sin publicar del archivo del Very Large Array tomados con una separación temporal de 8.09 años para confirmar los movimientos propios observados en el óptico en sus ansas. Determinamos valores de 23±6 y 34±10 mas año para las ansas este y oeste, respectivamente. Hay evidencia marginal de que las densidad...

Towards Proper Motions in the Local Group

Key and still largely missing parameters for measuring the mass content and distribution of the Local Group are the proper motion vectors of its member galaxies. The problem when trying to derive the gravitational potential of the Local Group is that usually only radial velocities are known, and hence statistical approaches have to be used. The expected proper motions for galaxies within the Lo...