Comet SW3 and XMM-Newton: an extremely close encounter with a flying laboratory

Collisions between stellar winds and their gaseous environments play animportant role in many areas of astrophysics. We propose to utilize XMMNewtonto study the Xray aurora produced by the collision of the solar wind with theneutral coma around the largest remaining fragment of comet SW3. Its extremelyclose encounter in May 2006 provides the opportunity to spatially resolve thedeceleration and depletion of the solar wind ions in the coma. In combinationwith laboratory atomic data, this provides a quantitative handle on theconditions throughout the interaction zone, which will greatly improve ourunderstanding of the interaction of the solar wind with solar system objects andin more general, of physical processes in windenvironment collisions. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]