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Doppler images and chromospheric variability of TWA 17 |
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| Authors: | M B Skelly Y C Unruh J R Barnes W A Lawson J-F Donati A Collier Cameron |
| Institution: | Astrophysics Group, Imperial College of Science, Technology and Medicine, London SW7 2AZ;Observatoire Midi-Pyrénées, LATT, 14 avenue Edouard Belin, 31400 Toulouse, France;Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, Herts AL10 9AB;School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Australian Defence Force Academy, Canberra, ACT 2600, Australia;School of Physics and Astronomy, University of St Andrews, Fife KY16 9SS |
| Abstract: | We present Doppler imaging and a Balmer line analysis of the weak-line T Tauri star TWA 17. Spectra were taken in 2006 with the University College London Echelle Spectrograph on the Anglo-Australian Telescope. Using least-squares deconvolution to improve the effective signal-to-noise ratio, we produced a Doppler map of the surface spot distribution. This shows similar features to maps of other rapidly rotating T Tauri stars, i.e. a polar spot with more spots extending out of it down to the equator. In addition to the photospheric variability, the chromospheric variability was studied using the Balmer emission. The mean Hα profile has a narrow component consistent with rotational broadening and a broad component extending out to 220 km s |
| Keywords: | stars: chromospheres stars: individual: TWA 17 stars: late-type stars: magnetic fields stars: pre-main-sequence stars: spots |