A small-scale extreme ultraviolet wave observed by SDO

National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011, China
e-mail: zhrsh@ynao.ac.cn

Abstract

“Extreme Ultraviolet (EUV) waves” are large-scale wavelike transients often associated with coronal mass ejections (CMEs). In this Letter, we present a possible detection of a fast-mode EUV wave associated with a mini-CME observed by the Solar Dynamics Observatory. On 2010 December 1, a small-scale EUV wave erupted near the disk center associated with a mini-CME, which showed all the low corona manifestations of a typical CME. The CME was triggered by the eruption of a mini-filament, with a typical length of about 30′′. Although the eruption was tiny, the wave had the appearance of an almost semicircular front and propagated at a uniform velocity of 220−250km s^-1 with very little angular dependence. The CME lateral expansion was asymmetric with an inclination toward north, and the southern footprints of the CME loops hardly shifted. The lateral expansion resulted in deep long-duration dimmings, showing the CME extent. Our analysis confirms that the small-scale EUV wave is a true wave, interpreted as the fast-mode wave.