title: The moving emission features in SS433 require a dynamical interpretation.
abstract: New spectrophotometry of SS433 shows that the variable-wavelength emission features discovered by Margon et al. are due to the simultaneous presence of material having a substantial redshift and a substantial blueshift. A magnetic interpretation for the features is also ruled out by polarimetric measurements. Implications for dynamical models are discussed.
authors.forename: J
authors.initials: J
authors.lastname: Liebert
authors.forename: J R
authors.initials: JR
authors.lastname: Angel
authors.forename: E K
authors.initials: EK
authors.lastname: Hege
authors.forename: P G
authors.initials: PG
authors.lastname: Martin
authors.forename: W P
authors.initials: WP
authors.lastname: Blair