Polarization observations and results of the 1998 February 26th solar eclipse
Abstract
Following our long-term solar corona study program, we organized an expedition to the Curacao island (Dutch Antillas) to observe the total solar eclipse of February 26th, 1998. As the duration of this totality was quite short, our polarized white-light CCD imaging experiment was redesigned in order to increase the number of recorded images, thereby increasing the number of sampled polarization angles and exposures. This was made possible by upgrading to a new PC system, with fast hard disc and data transfer port. This allowed us to finally record 7 series of different exposures, each containing 24 images taken at 12 polarization angles, i.e. with 8-time oversampling. The data were processed to derive global maps of brightness and polarization, and from these, to build electron density models. In those maps, the shape of the corona is highly flattened, with extended polar holes filled with numerous wide plumes. All large streamers are essentially aligned along the solar equatorial plane. Moreover, the measured degree of polarization indicates that these structures are located in the vicinity of the plane of the sky. Unfortunately, the unusually high sky brightness hid the faint extensions of coronal structures. This limited their visibility to less than 3 solar radii, implying a corresponding limitation in the radial extent of our global model. The results presented here are also briefly compared with our earlier eclipse observations.
- Publication:
-
Solar Wind Nine
- Pub Date:
- June 1999
- DOI:
- 10.1063/1.58725
- Bibcode:
- 1999AIPC..471..749G
- Keywords:
-
- 96.60.Pb;
- 95.10.Gi;
- Eclipses transits and occultations