Such a wind can be accelerated by radiation pressure in deep layers, which cannot be directly observed. This wind, whose velocity increases with time, overtakes and should collide with layers ejected before maximum, which are then swept up. There are, however, disagreements between me and an American team. Two review talks were given at meetings in 1999, of which one is still in press. V603 Aql, published in 1997 and based on observations made with the Hubble Space Telescope in 1994, we found rapid variations in the profiles of spectral lines.
Symbiotic binaries share certain properties with cataclysmic binaries.
The compact component, which appears to be in at least most cases a white dwarf, has a cool giant companion. Sometimes the giant seems to fill its Roche lobe and then should lose mass in the same way as the cool component of a cataclysmic binary. This explanation does not, however, appear to work for all symbiotics. Let us also mention VV Cephei type binaries, which contain an M type giant, accompagnied by a B star on or near the main sequence. Certain processes they undergo are the same as those of symbiotics.