First Evidence of Coexisting EIT Wave and Coronal Moreton Wave from SDO/AIA Observations

Abstract

"EIT waves" are a globally propagating wavelike phenomenon. They were often interpreted as a fast-mode magnetoacoustic wave in the corona, despite various discrepancies between the fast-mode wave model and observations. To reconcile these discrepancies, we once proposed that "EIT waves" are apparent propagation of the plasma compression due to successive stretching of the magnetic field lines pushed by the erupting flux rope. According to this model, an "EIT wave" should be preceded by a fast-mode wave, which however was rarely observed. With the unprecedented high cadence and sensitivity of the {\em Solar Dynamics Observatory} ({\em SDO}) observations, we discern a fast-moving wave front with a speed of 560 km s${}^{-1}$, ahead of an "EIT wave", which had a velocity of $\sim 190$ km s${}^{-1}$, in the "EIT wave" event on 2010 July 27. The results, suggesting that "EIT waves" are not fast-mode waves, confirm the prediction of our fieldline stretching model for "EIT wave". In particular, it is found that the coronal Moreton wave was $\sim 3$ times faster than the "EIT wave" as predicted.

13 pages, 4 figures, submitted for publication in ApJ Letters

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Cited by in corpus (8)

• Advances in Observing Various Coronal EUV Waves in the SDO Era and Their Seismological Applications (Invited Review)
• A Chain of Winking (Oscillating) Filaments Triggered by an Invisible Extreme-Ultraviolet Wave
• Statistical Analysis of Large-scale EUV Waves Observed by STEREO/EUVI
• MHD Seismology of a Coronal Loop System by the First Two Modes of Standing Kink Waves
• CorPITA: An Automated Algorithm for the Identification and Analysis of Coronal "EIT Waves"
• Partial Reflection and Trapping of a Fast-mode Wave in Solar Coronal Arcade Loops
• Prominence Activation by Coronal Fast Mode Shock
• Contribution of Velocity Vortices and Fast Shock Reflection and Refraction to the Formation of EUV Waves in Solar Eruptions