Osten, Rachel

Contact Email: raosten@casa.colorado.edu
Institute: CASA, University of Colorado
First Coauthor: Alexander Brown
Institute: CASA, University of Colorado
Second Coauthor: Jeffrey L. Linsky
Institute: JILA, University of Colorado, and NIST
Presenting Thesis: Yes
Subject Area: Stellar Atmospheres, Circumstellar Material
Waveband: Multi-wavelength
Technique: Spectroscopy
Presentation: Oral Contribution: Thursday
Title: Chandra, EUVE, and VLA Observations of the Active Binary System $\sigma^{2}$ Coronae Borealis
Abstract: We report on a multi-wavelength campaign to observe the short period (P $_{\rm orb}=$ 27.4 hr) active binary system $\sigma^{2}$ CrB (F6V + G0V) with Chandra ACIS-S+HETG, EUVE, and the VLA in 2000 June. Simultaneous radio and X-ray observations of flares provide insights into the thermal and non-thermal nature of the flare process. The EUVE observation spanned 8.3 days, in the middle of which occurred the 23.9 hour Chandra observation and the 10 hour VLA observation. Within the space of two consecutive orbital periods during EUVE's stare, the system underwent five flare events, the first of which was observed with Chandra. We discuss the search for flare-related and orbital phase-related motions in the bright lines of Ne X $\lambda$ 12.13 Å and Mg XII $\lambda$ 8.42 Å using the Chandra HETG data. We discuss data reduction and analysis of the Chandra observation, deriving electron densities, emission measure distributions, abundances of N, O, Ne, Mg, Al, Si, S, Ar, and F relative to H for quiescent and flaring conditions. We also discuss radio/X-ray correlations of flares.