Polar Exploration and Coronal Structure in the Active Binary HR 5110

Abstract

Overwhelming evidence exists for the importance of polar regions in controlling stellar atmospheric structure and dynamics in active binary systems. Uncertainties about the geometry of coronal emission have made conclusions about coronal structures on such stars ambiguous. We have obtained Chandra, VLA and VLBA observations of the nearly pole-on active binary system HR 5110 in order to investigate coronal structures without such ambiguity. The X-ray spectra will constrain thermal coronal volumes through determinaion of electron densities; radio observations will constrain non-thermal coronal volumes directly, and allow an estimation of the relative importance of thermal and nonthermal plasma in controlling and structuring active stellar coronae. Here we present preliminary results from the Chandra observations.

The Correlation Between X-Ray Line Ionization and Optical Spectral Types of the Ob Stars

“…We have combined the two datasets whenever possible, i.e., whenever the HEG S/N was adequate. The data discussed here were obtained from the TGCat (Huenemoerder et al 2009) web-based catalog of Chandra grating data. TGCat processing starts with the Level 1 event data downloaded from the Chandra archive.…”

“…This research made use of the Chandra Transmission Grating Catalogue and archive (Huenemoerder et al 2009). We thank Mr. Arik Mitschang for assistance with the line measurements and plots at the Center for Astrophysics.…”

Radio Astrometry of the Close Active Binary Hr 5110

“…This orientation is well-suited to investigate whether the radio emission is associated with a single component or with an interaction region. It also provides a convenient test of active region association with polar spots (Huenemoerder et al 2009), assuming the magnetic and rotational axes are parallel and normal to the orbital plane, and hence oriented toward the observer.…”