The results of observations of variable radial velocities of Alpha Cygni are presented for 1962 to 1977. The results are as follows: (1) Radial velocities of different metallic lines simultaneously change in the same sense and are correlated, in the same sense, to those of the core of the Hγ profile. The radial velocities for the core of the Hγprofile are almost more negative than the values for metallic lines (Si II, Fe II, Ca II), exclusive of Mg II λ4481. The velocities of Mg II λ4481 are usually more negative than those of Hγ. There are also Balmer velocity progressions of varying velocity gradients with time, and become steeper when the radial velocities of metallic lines become more negative. (2) the central line depths of the metallic lines and of the core of the Hγ profile, and the line depth of the apparent absorption minimum of the Hα profile become deeper when the radial velocities of the metallic lines become more negative. (3) The "line width" of the absorption feature of the Hα profile becomes broader as the line depth of the absorption minimum is increased. Variation in the apparent strength of the emission component of the Hα profile does not directly reflect the variation in the radial velocities of the metallic lines (Si II).The upper layer is always in an outward accelerating state with varying velocity gradients with time. The observations indicate that the variations are due to the temporary ejection of matter with an increased velocity and velocity gradient.
Publications of the Astronomical Society of Japan
- Pub Date:
- A Supergiants:Line Profiles;
- A Supergiants:Mass Loss;
- A Supergiants:P Cygni Profiles;
- A Supergiants:Radial Velocities