The impulsive phase of the solar flare, in which most energy is released. Panel (a) a snapshot of Hα + 1.0 Å image showing post-flare brightening associated with coronal rain. The white box marks the ROI where the brightenings occurred. Panel (b) the zoomed-in view of the ROI marked by the white box in panel (a). The slits, with different colors, mark where the brightenings’ cross-sectional width were measured. Panel (c) the pseudo Dopplergrams (with red corresponding to red shift) of the ROI. Panels (d–g) the normalized Hα + 1.0 Å intensity profiles along the slits and the Gaussian fits. For reference, the color of each profile is the same as the color of the slit (see panel b). The Gaussian FWHM and ±3σ are provided in the panels. Credit: NJIT
High-resolution images capture a solar flare as it unfolds. Scientists at NJIT’s Big Bear Solar Observatory (BBSO) have captured unprecedented images of a recent solar flare, including bright flare ribbons seen crossing a sunspot followed by “coronal rain,” plasma that condenses in the cooling phase shortly after the flare, showering the visible surface of the Sun where it lands in brilliant explosions. The new images provide insights into one of the central puzzles of solar physics – how energy is transferred from one region of the Sun to another during and after a solar flare, an explosive release of magnetic energy responsible for space weather.
Panel (a) GOES soft X-ray 1–8 Å light curve. The vertical dotted line indicates the time 18:13:22 UT. The SDO/AIA and NST/VIS images shown in panels (b–d) were all taken within 6 s from this time. Panel (b) the full-disk SDO/AIA 1600 Å map. It serves as the reference to register the NST’s FOV with heliographic coordinates. The white box outlines the region of interest (ROI) where the flare occurred. Panel (c) a blend of NST/VIS Hα + 1.0 Å image and a larger SDO/AIA 1600 Å map. The field-of-view (FOV) of panel (c) is the same as the boxed region in panel (b). Panel (d) the zoomed-in view of the NST/VIS image in panel (c).
“We can now observe in very fine detail how energy is transported in solar flares, in this case from the corona where it has been stored to the lower chromosphere tens of thousands of miles below it, where most of the energy is finally converted into heat and radiated away,” said Prof. Ju Jing, NJIT. While electron beams are traditionally seen as the major agent for transporting flare energy, the new observations provide novel information on the spatial scale of the energy transport.
Panel (a) a snapshot of Hα + 1.0 Å image taken in the impulsive phase of the flare. Four boxes (labelled from ‘b’ to ‘e’) mark the FOV of the zoomed-in images in panels (b–e) in this figure. Panels (b–e) four blends of the Hα + 1.0 Å images (gray scale) and the associated pseudo Dopplergrams (with red corresponding to red shift), at selected times. In each panel the slit cross-cutting the red-shifted leading edge of the flare shows where the cross-sectional width was measured. Panels (f–i) the normalized pseudo Dopplergram intensity profile (red dots) along the slit in the top panel and the Gaussian fit (black curve). The Gaussian FWHM and ±3σ are provided in each panel.
Captured by NJIT’s 1.6m New Solar Telescope (NST) during a solar flare on June 22, 2015, the images of coronal rain are among a series of recent pictures providing scientists new insights into the complex dynamics of the Sun’s multi-layered atmosphere and massive eruptions. NST’s high-res observations have led to new information on all phases of solar flares, including instability of magnetic flux tubes that can trigger flares, behavior of the bright flare ribbons in the initial phase of flares, and new observations of cooling phase.
The newly revealed solar phenomena will lead, the researchers hope, to a better understanding of their impact on Earth. http://www.njit.edu/features/innovations/ju-solar-flare.php?utm_source=njit&utm_medium=home&utm_content=news&utm_campaign=teaser http://www.nature.com/articles/srep24319
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