A coronal blowout jet associated with a double-CME and shock wave

Based on high-resolution {\sl Big Bear Solar Observatory} ({\sl BBSO}), {\sl Solar Dynamics Observatory} ({\sl SDO}) and {\sl Solar Terrestrial Relations Based on high-resolution {\sl Big Bear Solar Observatory} ({\sl BBSO}), {\sl Solar Dynamics Observatory} ({\sl SDO}) and {\sl Solar Terrestrial Relations Observatory} ({\sl STEREO}) data, AR NOAA 11166 (on March 09, 2011) is found to be the theater of a small H$\alpha$ filament eruption during a blowout jet phase, whose length is estimated to be larger than 400 Mm with an average velocity of about \speed{270}. An evident magnetic flux cancellation is observed on the photosphere during the double-CME blowout jet. The blowout jet is found to show an unwinding motion during the eruption phase. Interestingly, using {\sl SDO}/AIA 193 \AA\ observations, a short time shock wave is reported at the beginning of the eruption. From {\ sl SDO} viewpoint, the bubble-like CME was formed by the front part of the jet, while the jet-like CME was formed by the rectilinear part of the jet. Additionally, from {\sl STEREO} COR1 A and B viewpoints, an overlapping of the two CMEs were due to the special magnetic field distribution on the photosphere that we depict in a simple sketch model. The studied event, blowout jet with two simultaneous CMEs, with its atypical structures indicates again that a variety of solar activities with different spatial scales might simultaneously take place and integrate into one solar eruption phenomenon.