Observations of penumbral wave in the photosphere.
Abstract
Simultaneous observations have been made of velocities in the chromosphere (in H-alpha) and in the photosphere (in the nonmagnetic Fe I line at 5526-A) of three sunspots. The results reveal waves propagating horizontally outward across the penumbra in the photosphere with about the same period as the running penumbral waves in H-alpha (250-290 s). The photospheric waves are more intermittent and have higher horizontal phase velocity (by a factor of 2 or more) than the chromospheric penumbral waves.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1976
- DOI:
- 10.1086/182161
- Bibcode:
- 1976ApJ...206L.175M
- Keywords:
-
- Chromosphere;
- Penumbras;
- Photosphere;
- Solar Atmosphere;
- Sunspots;
- H Alpha Line;
- Phase Velocity;
- Wave Propagation;
- Solar Physics