  We present and interpret the observations of extreme ultraviolet (EUV) waves
associated with a filament eruption on 2011 May 11.The filament eruption also
produces a small B-class two ribbon flare and a coronal mass ejection (CME).
The event is observed by the Solar Dynamic Observatory (SDO) with high
spatio-temporal resolution data recorded by Atmospheric Imaging Assembly (AIA).
As the filament erupts, we observe two types of EUV waves (slow and fast)
propagating outwards. The faster EUV wave has a propagation velocity of ~ 500
km/s and the slower EUV wave has an initial velocity of ~ 120 km/s. We report
for the first time that not only the slower EUV wave stops at a magnetic
separatrix to form bright stationary fronts, but also the faster EUV wave
transits a magnetic separatrix, leaving another stationary EUV front behind.
