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Title: THERMODYNAMICS OF THE SOLAR CORONA AND EVOLUTION OF THE SOLAR MAGNETIC FIELD AS INFERRED FROM THE TOTAL SOLAR ECLIPSE OBSERVATIONS OF 2010 JULY 11

Journal Article · · Astrophysical Journal
;  [1]; ;  [2];  [3];  [4];  [5];  [6];  [7];  [8]
  1. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
  2. Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2, 616 69 Brno (Czech Republic)
  3. Institute of Optics and Atomic Physics, Technische Universitaet Berlin, and Institute of Technical Physics, Berlin (Germany)
  4. Electricon, Boulder, CO 80204 (United States)
  5. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
  6. Physics Department, Bridgewater State University, Bridgewater, MA 02325 (United States)
  7. ASTELCO, Munich (Germany)
  8. Department of Physics and Astronomy, Appalachian State University, Boone, NC 28608 (United States)

We report on the first multi-wavelength coronal observations, taken simultaneously in white light, H{alpha} 656.3 nm, Fe IX 435.9 nm, Fe X 637.4 nm, Fe XI 789.2 nm, Fe XIII 1074.7 nm, Fe XIV 530.3 nm, and Ni XV 670.2 nm, during the total solar eclipse of 2010 July 11 from the atoll of Tatakoto in French Polynesia. The data enabled temperature differentiations as low as 0.2 x 10{sup 6} K. The first-ever images of the corona in Fe IX and Ni XV showed that there was very little plasma below 5 x 10{sup 5} K and above 2.5 x 10{sup 6} K. The suite of multi-wavelength observations also showed that open field lines have an electron temperature near 1x 10{sup 6} K, while the hottest, 2x 10{sup 6} K, plasma resides in intricate loops forming the bulges of streamers, also known as cavities, as discovered in our previous eclipse observations. The eclipse images also revealed unusual coronal structures, in the form of ripples and streaks, produced by the passage of coronal mass ejections and eruptive prominences prior to totality, which could be identified with distinct temperatures for the first time. These trails were most prominent at 10{sup 6} K. Simultaneous Fe X 17.4 nm observations from Proba2/SWAP provided the first opportunity to compare Fe X emission at 637.4 nm with its extreme-ultraviolet (EUV) counterpart. This comparison demonstrated the unique diagnostic capabilities of the coronal forbidden lines for exploring the evolution of the coronal magnetic field and the thermodynamics of the coronal plasma, in comparison with their EUV counterparts in the distance range of 1-3 R{sub sun}. These diagnostics are currently missing from present space-borne and ground-based observatories.

OSTI ID:
21576590
Journal Information:
Astrophysical Journal, Vol. 734, Issue 2; Other Information: DOI: 10.1088/0004-637X/734/2/120; ISSN 0004-637X
Country of Publication:
United States
Language:
English