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Title: Qualities of sequential chromospheric brightenings observed in Hα and UV images

Chromospheric flare ribbons observed in Hα appear well-organized when first examined: ribbons impulsively brighten, morphologically evolve, and exponentially decay back to pre-flare levels. Upon closer inspection of the Hα flares, there is often a significant number of compact areas brightening in concert with the flare eruption but are spatially separated from the evolving flare ribbon. One class of these brightenings is known as sequential chromospheric brightenings (SCBs). SCBs are often observed in the immediate vicinity of erupting flares and are associated with coronal mass ejections. In the past decade there have been several previous investigations of SCBs. These studies have exclusively relied upon Hα images to discover and analyze these ephemeral brightenings. This work employs the automated detection algorithm of Kirk et al. to extract the physical qualities of SCBs in observations of ground-based Hα images and complementary Atmospheric Imaging Assembly images in He II, C IV, and 1700 Å. The metadata produced in this tracking process are then culled using complementary Doppler velocities to isolate three distinguishable types of SCBs. From a statistical analysis, we find that the SCBs at the chromospheric Hα layer appear earlier and last longer than their corresponding signatures measured in AIA. From this multi-layermore » analysis, we infer that SCBs are spatially constrained to the mid-chromosphere. We also derive an energy budget to explain SCBs which have a postulated energy of not more than 0.01% of the total flare energy.« less
Authors:
 [1] ; ; ;  [2]
  1. NASA Goddard Space Flight Center, Code 670, Greenbelt, MD 20771 (United States)
  2. Department of Astronomy, New Mexico State University, P.O. Box 30001, MSC 4500, Las Cruces, NM 88003 (United States)
Publication Date:
OSTI Identifier:
22370169
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 796; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CHROMOSPHERE; DECAY; DETECTION; ENERGY BALANCE; ERUPTION; INSPECTION; LAYERS; MASS; SUN; VELOCITY