Formation of Network Bright Points by Granule Compression
Abstract
Network Bright Points (NBPs) are tiny, subarcsecond, bright features, visible in high-resolution filtergrams taken in white light as well as in photospheric and chromospheric absorption lines. They form the photospheric network and are associated with kilogauss, concentrated magnetic fields. Their behaviour is studied in a 3-hour, high-resolution granulation movie recorded at the Pic-du-Midi Observatory and processed at Lockheed Palo Alto Research Laboratory. The movie shows the important role played by granules. It appears that NBPs are formed in dark spaces when surrounding granules converge to fill this space. The formation is a fast phenomenon which lasts only 4 min. The lifetime of NBPs is 18 min on the average. About 15% of them split when they are squeezed between two expanding granules. Some consequences concerning the strength of the magnetic field during the formation of NBPs are discussed.
- Publication:
-
Solar Physics
- Pub Date:
- September 1992
- DOI:
- 10.1007/BF00155901
- Bibcode:
- 1992SoPh..141...27M
- Keywords:
-
- Brightness Temperature;
- Filtergrams;
- Magnetic Signatures;
- Photosphere;
- Solar Granulation;
- Solar Magnetic Field;
- High Resolution;
- Solar Atmosphere;
- Solar Observatories;
- Sunspots;
- Solar Physics;
- Magnetic Field;
- Research Laboratory;
- Palo Alto;
- White Light;
- Absorption Line