THE FIRST X-RAY SPECTROSCOPY OBSERVATION OF WO BINARY

We propose a 50 ksec XMMNewton observation of a massive stellar binary WR30a.The binary consists of a WOtype WolfRayet star and an O type companion. AWOtype star is generally thought to be the final evolutionary stage in the WRphase, and has the fastest stellar wind with average terminal velocity approx5000 km s1. To date, there is no report on Xray detection from WOtype stars,while intensive studies have been made for WN and WC type stars with Xrays.Our aim is to detect Xrays from a WOtype binary for the first time, and tocompare the Xray properties (especially the plasma temperature) with those ofwellresearched two types (WN and WC). truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]