The Sun in STEREO
Some images are already available. The illustrations below present a range of them. Amongst the first Earth bound solar ejections recorded by STEREO some were visible at distances of half an astronomical unit from the Sun!
The STEREO mission should last for at least two years. The work of the engineer Jean-Philippe Halain and his colleagues, who designed the on-board instruments, will not stop even though the satellites have been placed in their orbits. Jean-Philippe Halain in particular continues to analyse the observations carried out by the heliospheric imager to check its behaviour and performance in space, to make sure that light interference is effectively reduced and to reset the instrument if necessary. This engineering work, often carried out behind the scenes, provides a precise model of the instrument’s optic system, and allows scientists to rigorously interpret the observations later.