STEREO observed stealth CME

Introduction

The twin STEREO probes are two identical spacecraft, one flying ahead (A) of the Earth and one flying behind it (B). They were launched on Wednesday, October 25th, 2006 from Cape Canaveral, Florida. The separation angle between the two spacecraft increases as time progresses, on June 1st 2008, this angle was <math>53^{\circ}</math>.

Figure 1: Schematic view of the CME direction projected on the ecliptic plane (top view). The separation angle between the A and B spacecraft was 53<math>^{\circ}</math>. The CME traveled towards STEREO B and was clearly visible in coronagraph images from STEREO A.