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ULTRA-NARROW NEGATIVE FLARE FRONT OBSERVED IN HELIUM-10830 Å USING THE 1.6 m NEW SOLAR TELESCOPE.

Authors :
Yan Xu
Wenda Cao
Mingde Ding
Lucia Kleint
Jiangtao Su
Chang Liu
Haisheng Ji
Jongchul Chae
Ju Jing
Kyuhyoun Cho
Kyungsuk Cho
Dale Gary
Haimin Wang
Source :
Astrophysical Journal; 3/10/2016, Vol. 819 Issue 2, p1-1, 1p
Publication Year :
2016

Abstract

Solar flares are sudden flashes of brightness on the Sun and are often associated with coronal mass ejections and solar energetic particles that have adverse effects on the near-Earth environment. By definition, flares are usually referred to as bright features resulting from excess emission. Using the newly commissioned 1.6 m New Solar Telescope at Big Bear Solar Observatory, we show a striking “negative” flare with a narrow but unambiguous “dark” moving front observed in He i 10830 Å, which is as narrow as 340 km and is associated with distinct spectral characteristics in Hα and Mg ii lines. Theoretically, such negative contrast in He i 10830 Å can be produced under special circumstances by nonthermal electron collisions or photoionization followed by recombination. Our discovery, made possible due to unprecedented spatial resolution, confirms the presence of the required plasma conditions and provides unique information in understanding the energy release and radiative transfer in astronomical objects. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
0004637X
Volume :
819
Issue :
2
Database :
Complementary Index
Journal :
Astrophysical Journal
Publication Type :
Academic Journal
Accession number :
113873249
Full Text :
https://doi.org/10.3847/0004-637X/819/2/89