Variable wind-velocity in 59 Cyg.
Abstract
Combined UV and visual observations of 59 Cyg in 1972, 1975, late 1978, and at several epochs in 1979 are summarized. Visual observations suggest a similar pattern of long term variability for 59 Cyg and gamma Cas, within which are placed the UV data on 59 Cyg. During the 1978-79 epoch of small but increasing H alpha emission, the C4 and N5 lines reached maximum expansion velocities of some 750 km/sec, whereas the Si4 lines showed neither appreciable displacements nor asymmetry. Line displacements of N5 varied by a factor 2, and appeared to oscillate, but line components that correspond to violet displacements 100 km/s were not identified. This 1978-79 situation is unlike the situation of strong Be phase of 59 Cyg in 1972 and 1975, and of Gamma Cas in 1978-79, where expansion at less than 100 km/s was observed.
- Publication:
-
Ultraviolet observations of Quasars
- Pub Date:
- April 1980
- Bibcode:
- 1980ESASP.157..151D
- Keywords:
-
- Astronomy;
- B Stars;
- Iue;
- Stellar Mass Ejection;
- Stellar Winds;
- Chromosphere;
- Cygnus Constellation;
- Emission Spectra;
- H Alpha Line;
- Line Spectra;
- Variable Stars