skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: FIRST OBSERVATIONS OF A DOME-SHAPED LARGE-SCALE CORONAL EXTREME-ULTRAVIOLET WAVE

Journal Article · · Astrophysical Journal Letters
; ; ;  [1];  [2]
  1. Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria)
  2. Hvar Observatory, Faculty of Geodesy, Kaciceva 26, 1000 Zagreb (Croatia)

We present first observations of a dome-shaped large-scale extreme-ultraviolet coronal wave, recorded by the Extreme Ultraviolet Imager instrument on board STEREO-B on 2010 January 17. The main arguments that the observed structure is the wave dome (and not the coronal mass ejection, CME) are (1) the spherical form and sharpness of the dome's outer edge and the erupting CME loops observed inside the dome; (2) the low-coronal wave signatures above the limb perfectly connecting to the on-disk signatures of the wave; (3) the lateral extent of the expanding dome which is much larger than that of the coronal dimming; and (4) the associated high-frequency type II burst indicating shock formation low in the corona. The velocity of the upward expansion of the wave dome (v {approx} 650 km s{sup -1}) is larger than that of the lateral expansion of the wave (v {approx} 280 km s{sup -1}), indicating that the upward dome expansion is driven all the time, and thus depends on the CME speed, whereas in the lateral direction it is freely propagating after the CME lateral expansion stops. We also examine the evolution of the perturbation characteristics: first the perturbation profile steepens and the amplitude increases. Thereafter, the amplitude decreases with r {sup -2.5{+-}0.3}, the width broadens, and the integral below the perturbation remains constant. Our findings are consistent with the spherical expansion and decay of a weakly shocked fast-mode MHD wave.

OSTI ID:
21451127
Journal Information:
Astrophysical Journal Letters, Vol. 716, Issue 1; Other Information: DOI: 10.1088/2041-8205/716/1/L57; ISSN 2041-8205
Country of Publication:
United States
Language:
English