Gondoin, Philippe Daniel Alain

Contact Email: pgondoin@astro.estec.esa.nl
Institute: European Space Agency - Space Science
Department
First Coauthor: C. Erd
Institute: European Space Agency - Space Science Department
Second Coauthor: D. Lumb
Institute: European Space Agency - Space Science Department
Research URL:http://astro.estec.esa.nl/
Subject Area: Single Stars
Waveband: X-rays
Technique: Spectroscopy
Presentation: Oral Presentation: Monday
Title: XMM-Newton Spectroscopy of FK Comae
Abstract: FK Comae (HD 117155) is a rapidly rotating single G giant whose distinctive characteristics include strong and variable H$\alpha$ and Ca II emissions, strong UV chromospheric emission lines, a quasi-sinusoidal optical light curve and a high X-ray luminosity. FK Comae was observed twice at two weeks interval in January 2001 by the XMM-Newton space observatory. Its X-ray flux was strongly variable during both observations with count rate fluctuations greater than two in the 0.5-10 keV energy band. However, the two light curves are different. In the first observation, the flux increased steadily during 15 ksec up to a high count rate which remained stable for the rest of the exposure. On the contrary, during the second observation, the flux increased and decreased on a shorter period. We will report the analysis results of the spectra registered during these two observations by the EPIC cameras and the Reflection Grating Spectrometers on board XMM-Newton. The X-ray luminosity of FK Comae will be compared with that of single field giants within the frame of stellar activity evolution across the Hertzsprung gap.