caa a22 4500 445346027 CHVBK 20180317142829.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s11207-011-9732-7 doi (NATIONALLICENCE)springer-10.1007/s11207-011-9732-7 Spectroscopic Observation of Oscillations in the Corona During the Total Solar Eclipse of 22 July 2009 [Elektronische Daten] [Jagdev Singh, S. Hasan, G. Gupta, K. Nagaraju, D. Banerjee] We performed high resolution spectroscopy of the solar corona during the total solar eclipse of 22 July 2009 in two emission lines: the green line at 5303Å due to Fexiv and the red line at 6374Å due to Fex, simultaneously from Anji (latitude 30°28.1′ N; longitude 119°35.4′ E; elevation 890m), China. A two-mirror coelostat with 100cm focal length lens produced a 9.2mm image of the Sun. The spectrograph using 140 cm focal length lens in Littrow mode and a grating with 600 lines per millimeter blazed at 2μm provided a dispersion of 30mÅ and 43mÅ per pixel in the fourth order around the green line and third order around the red line, respectively. Two Peltier cooled 1k × 1k CCD cameras, with a pixel size of 13μm square and 14-bit readout at 10 MHz operated in frame transfer mode, were used to obtain the time sequence spectra in two emission lines simultaneously. The duration of totality was 341s, but we could get spectra for 270s after a trial exposure at an interval of 5s. We report here on the detection of intensity, velocity, and line width oscillations with periodicity in the range of 25 - 50s. These oscillations can be interpreted in terms of the presence of fast magnetoacoustic waves or torsional Alfvén waves. The intensity ratios of green to red emission lines indicate the temperature of the corona to be 1.65MK in the equatorial region and 1.40MK in the polar region, relatively higher than the expected temperature during the low activity period. The width variation of the emission lines in different coronal structures suggests different physical conditions in different structures. Springer Science+Business Media B.V., 2011 Coronal heating nationallicence Emission lines nationallicence MHD waves nationallicence Oscillations nationallicence Solar corona nationallicence Singh Jagdev Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut Hasan S. Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut Gupta G. Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut Nagaraju K. Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut Banerjee D. Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut Solar Physics Springer Netherlands 270/1(2011-05-01), 213-233 0038-0938 270:1<213 2011 270 11207 https://doi.org/10.1007/s11207-011-9732-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-011-9732-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Singh Jagdev Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut NATIONALLICENCE 700 1- Hasan S. Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut NATIONALLICENCE 700 1- Gupta G. Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut NATIONALLICENCE 700 1- Nagaraju K. Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut NATIONALLICENCE 700 1- Banerjee D. Indian Institute of Astrophysics, Koramangala, 560034, Bangalore, India aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 270/1(2011-05-01), 213-233 0038-0938 270:1<213 2011 270 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer