Schmitt, Juergen H.M.M.

Contact Email: jschmitt@hs.uni-hamburg.de
Institute: Hamburger Sternwarte
First Coauthor: Reiner Wichmann
Institute: Hamburger Sternwarte
Research URL:http://www.hs.uni-hamburg.de
Subject Area: Stellar Atmospheres, Circumstellar Material
Waveband: Optical
Technique: Spectroscopy
Presentation: Poster Display
Title: Ground-based discovery of coronal line emission with the VLT
Abstract: We have detected coronal line emission from the ground in the red dwarf CN Leo using UVES on the ESO VLT. As far as we are aware, this is the first time that such a detection attempt has been successful. We have detected the Fe XIII 3388 Angstrom line. This line is clearly resolved. It is very broad and the line width indicates formation away from the peak of the ionisation curve and/or turbulent broadening. From the measured intensity we can derive emission measures which are consistent with previously (and non-simultaneously) obtained X-ray emission measures. Our discovery closes the historical loop to the solar corona which was originally detected in such forbidden lines. As a consequence we can detect and diagnose thermal emission from coronae from the ground rather from space and thus a new window to observing coronal emission has been opened. The implications of our detection for future work (Doppler imaging, coronal cycles) will also be discussed. In addition to the detection of the Fe XIII line, numerous chromospheric emission lines have been detected, which will allow far more detailed chromospheric modelling than hitherto possible.