Spectroscopic studies of solar corona VI: Trend in line-width variation of coronal emission lines with height independent of the structure of coronal loops

2006 ◽  
Vol 27 (2-3) ◽  
pp. 115-124 ◽  
Author(s):  
Jagdev Singh ◽  
Takashi Sakurai ◽  
Kiyoshi Ichimoto ◽  
S. Muneer
Keyword(s):  
Solar Corona ◽  
Line Width ◽  
Spectroscopic Studies ◽  
Emission Lines ◽  
Coronal Loops ◽  
Coronal Emission

scholarly journals The Sun-Spectroscopic Observations of the Coronal Emission Lines and ADITYA-1 Mission

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Jagdev Singh
Keyword(s):  
High Resolution ◽  
Solar Corona ◽  
Large Body ◽  
Solar Limb ◽  
Emission Lines ◽  
Coronal Loops ◽  
The Sun ◽  
Coronal Emission ◽  
Spectroscopic Observations ◽  
Line Widths

The sun and the solar atmosphere, known as solar corona have been studied in detail for centuries but still lot need to be understood about the sun. In the late 19th and earlier 20th century, the information gathered about the solar corona was from the brief moments available during the total solar eclipses. In the later part space observations provided a large body of information about the solar corona. We obtained systematic high resolution spectroscopic observations in [Fe x] 637.4 [Fe xi] 789.2, [Fe xiii] 1074.7, and [Fe xiv] 530.3 nm emission lines during the period of 1997-2007 with the 25-cm coronagraph at Norikura, Japan. The variation in line widths with height above the solar limb implies that one pair of lines indicate that top of coronal loops are hotter where as other pair of lines shows that loop top is cooler. To explain these results, we proposed an empirical model as all these results are difficult to explain using the existing models. With this background we planned and designed a visible emission line coronagraph (VELC). This instrument is in advance stage of fabrication and is expected to be launched in 2019-20. The challenges and required technical development for this mission are discussed.

scholarly journals The Sun-Spectroscopic Observations of the Coronal Emission Lines and ADITYA-1 Mission

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Jagdev Singh
Keyword(s):  
High Resolution ◽  
Solar Corona ◽  
Large Body ◽  
Solar Limb ◽  
Emission Lines ◽  
Coronal Loops ◽  
The Sun ◽  
Coronal Emission ◽  
Spectroscopic Observations ◽  
Line Widths

The sun and the solar atmosphere, known as solar corona have been studied in detail for centuries but still lot need to be understood about the sun. In the late 19th and earlier 20th century, the information gathered about the solar corona was from the brief moments available during the total solar eclipses. In the later part space observations provided a large body of information about the solar corona. We obtained systematic high resolution spectroscopic observations in [Fe x] 637.4 [Fe xi] 789.2, [Fe xiii] 1074.7, and [Fe xiv] 530.3 nm emission lines during the period of 1997-2007 with the 25-cm coronagraph at Norikura, Japan. The variation in line widths with height above the solar limb implies that one pair of lines indicate that top of coronal loops are hotter where as other pair of lines shows that loop top is cooler. To explain these results, we proposed an empirical model as all these results are difficult to explain using the existing models. With this background we planned and designed a visible emission line coronagraph (VELC). This instrument is in advance stage of fabrication and is expected to be launched in 2019-20. The challenges and required technical development for this mission are discussed.

scholarly journals Spectroscopic Studies of the Solar Corona II. Properties of Green and Red Emission Lines in Open and Closed Coronal Structures

2002 ◽  
Vol 54 (5) ◽  
pp. 793-806 ◽  
Author(s):  
Jagdev Singh ◽  
Takashi Sakurai ◽  
Kiyoshi Ichimoto ◽  
Yoshinori Suematsu ◽  
Aki Takeda
Keyword(s):  
Solar Corona ◽  
Spectroscopic Studies ◽  
Emission Lines ◽  
Red Emission ◽  
Coronal Structures

Rotational Characteristics of the Green Solar Corona: 1947-1991

1994 ◽  
Vol 144 ◽  
pp. 139-141 ◽  
Author(s):  
J. Rybák ◽  
V. Rušin ◽  
M. Rybanský
Keyword(s):  
Solar Corona ◽  
World Wide ◽  
Rotation Period ◽  
Original Data ◽  
Coronal Emission ◽  
Time Intervals ◽  
Data Set ◽  
The World ◽  
Coronal Emission Line ◽  
Homogeneous Data

AbstractFe XIV 530.3 nm coronal emission line observations have been used for the estimation of the green solar corona rotation. A homogeneous data set, created from measurements of the world-wide coronagraphic network, has been examined with a help of correlation analysis to reveal the averaged synodic rotation period as a function of latitude and time over the epoch from 1947 to 1991.The values of the synodic rotation period obtained for this epoch for the whole range of latitudes and a latitude band ±30° are 27.52±0.12 days and 26.95±0.21 days, resp. A differential rotation of green solar corona, with local period maxima around ±60° and minimum of the rotation period at the equator, was confirmed. No clear cyclic variation of the rotation has been found for examinated epoch but some monotonic trends for some time intervals are presented.A detailed investigation of the original data and their correlation functions has shown that an existence of sufficiently reliable tracers is not evident for the whole set of examinated data. This should be taken into account in future more precise estimations of the green corona rotation period.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

The Origin of Coronal Emission Lines.

1964 ◽  
Vol 140 ◽  
pp. 1192 ◽  
Author(s):  
M. H. L. Pryce
Keyword(s):  
Emission Lines ◽  
Coronal Emission
Sign in / Sign up

Export Citation Format

Share Document