Astronomers have long desired to study the rapid changes and evolution of the astronomical phenomena they observe. However, other than studies of long-term proper motions this has, to date, only been possible inside our Solar System. The images of Shoemaker-Levy 9 colliding with Jupiter and the complex motions in the Sun's atmosphere revealed by the Yohkoh X-ray satellite are two impressive examples. With the advent of routine 43 GHz VLBI and a year-round array such as the VLBA it is now possible to monitor the rapid structural changes that occur in the inner circumstellar envelope/outer photosphere of Mira variables through multi-epoch observations of SiO masers. We shall present a movie of this changing structure that covers 1.5 cycles of the Mira's pulsation period. The data show the effects of the strong shocks and magnetic fields that permeate the maser environment. They also demonstrate that the mass-loss process is complex and cannot be adequately described by current theoretical models.
|Original language||English (US)|
|Title of host publication||Galaxies and their Constituents at the Highest Angular Resolutions|
|State||Published - Jan 1 2001|
|Name||Proceedings of IAU Symposium|