AAS 201st Meeting, January, 2003
Session 60. Star Formation I
Oral, Tuesday, January 7, 2003, 10:00-11:30am, 602-604

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[60.06] Magnetically confined Plasmas in Very Young Massive Stars

N. S. Schulz, D. Huenemoerder, C. R. Canizares, K. Tibetts (MIT)

Early results from high resolution X-ray spectra of hot stars opened a new chapter in the diagnostics and understanding of the properties of stellar plasmas. Recent Chandra observations of several very young early type stars, especially in the Orion Trapezium, clearly challenged conventional model of shock heated plasmas to be the source of the X-ray flux in hot stars. The Orion Trapezium stars distinguish themselves from all the others by their extreme youth. Measured temperatures of 50 to 70 MK in early type stars like Theta Ori, A, C, and E within 75 to 80% of the X-ray emissivity are not compatible with standard models. The persistent high luminosities in the high temperature components also render dominating effects due to late-type companions unlikely. Symmetric and unresolved lines in all cases point in direction of magnetically confined plasmas. The sum of the results raise questions about the early evolution of massive stars.

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