Empirical atmospheric velocity patterns from combined IUE and visual observations : the Be stars.
Abstract
Observations of 59 Cyg show the strongest displacements of the far UV superionized lines at epochs of minimum H alpha emission. Phases of strongest mass flux, measured in the chromospheric coronal regions, do not coincide with phases of largest mass content in the overlying cool H alpha envelope. Velocities in the chromosphere-corona range up to 1500 km/sec; those in the H alpha and Fe II emission envelope, and absorption shell, do not exceed 1 to 200 km/sec. The density in the postcoronal regions is not fixed by a monotonically-outward accelerated flow; strong deceleration and cooling of the mass-flow within a few radii are required. The Be stars have the same atmospheric pattern as planetary nebulae but the decelerated cool regions occur within a few radii as contrasted to the 1 million or more radii for normal planetary nebulae.
- Publication:
-
Third European IUE Conference
- Pub Date:
- June 1982
- Bibcode:
- 1982ESASP.176..287D
- Keywords:
-
- Astronomy;
- B Stars;
- Stellar Atmospheres;
- Stellar Mass;
- Velocity Distribution;
- H Alpha Line;
- Iue;
- Planetary Nebulae;
- Stellar Coronas;
- Stellar Envelopes