Optical images and high–dispersion spectra have been obtained of the ejected material surrounding the pulsating AGB star Mira A .
The two streams of knots on either side of the star , found in far ultra–viollet ( FUV ) GALEX images , have now been imaged clearly in the light of H \alpha .
Spatially resolved profiles of the same line reveal that the bulk of these knots form a bi–polar outflow with radial velocity extremes of \pm 150 km s ^ { -1 } with respect to the central star .
The South stream is approaching and the North stream receding from the observer .
A displacement away from Mira A between the position of one of the South stream knots in the new H \alpha image and its position in the previous Palomar Observatory Sky Survey ( POSS I ) red plate has been noted .
If interpreted as a consequence of expansion proper motions the bipolar outflow is tilted at 69 ^ { \circ } \pm 2 ^ { \circ } to the plane of the sky , has an outflow velocity of 160 \pm 10 km s ^ { -1 } and is \approx 1000 y old .