AAS 203rd Meeting, January 2004
Session 93 Stars, Their Facts and Legends
Poster, Wednesday, January 7, 2004, 9:20am-6:30pm, Hanover Hall

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[93.07] An XMM-Newton Study of \sigma2 Coronae Borealis

J.A. Suh, M. Audard (Columbia Astrophysics Laboratory), M. Güdel (Paul Scherrer Institut)

We present results of XMM-Newton Guaranteed Time observations of the RS CVn binary \sigma2 Coronae Borealis (F9 V + G0 V). The spectra obtained with the Reflection Grating Spectrometers and the European Photon Imaging Cameras were simultaneously fitted with collisional ionization equilibrium plasma models to determine coronal abundances of various elements. Contrary to the solar FIP effect in which elements with a low first ionization potential (FIP) are overabundant in the corona compared to the solar photosphere, and contrary to the "inverse" FIP effect observed in several active RS CVn binaries, coronal abundances in \sigma2 CrB do not show a significant pattern related to the FIP. This is supported by similar findings in the Chandra HETGS analysis of \sigma2 CrB with a different methodology (Osten et al. 2003). We also report low densities (< 4 \times 1010 cm-3) from line ratios in the OVII He-like triplet.

The Columbia group was supported by a grant from NASA to Columbia University for XMM-Newton mission support and data analysis.

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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.