SIMBAD references

2008MNRAS.385..708S - Mon. Not. R. Astron. Soc., 385, 708-718 (2008/April-1)

Doppler images and chromospheric variability of TWA 6.

SKELLY M.B., UNRUH Y.C., COLLIER CAMERON A., BARNES J.R., DONATI J.-F., LAWSON W.A. and CARTER B.D.

Abstract (from CDS):

We present Doppler imaging and Balmer line analysis of the weak-line T Tauri star TWA 6. Using these data we have made one of the first attempts to measure differential rotation in a T Tauri star, and the first detection of a slingshot prominence in such a star. We also show the most direct evidence to date of the existence of solar-type plages in a star other than the Sun.

Observations were made over six nights: 2006 February 11-13 and 2006 February 18-20, when spectra were taken with the UCL Echelle Spectrograph on the 3.9-m Anglo-Australian Telescope. Using least-squares deconvolution to improve the effective signal-to-noise ratio we produced two Doppler maps. These show 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 equator. Comparison of the two maps was carried out to measure the differential rotation. Cross-correlation and parameter fitting indicates that TWA 6 does not have detectable differential rotation.

The Balmer emission of the star was studied. The mean Hα profile has a narrow component consistent with rotational broadening and a broad component extending out to ±250km/s. The variability in Hα suggests that the chromosphere has active regions that are cospatial with the spots in the photosphere, similar to the `plages' observed on the Sun. In addition the star has at least one slingshot prominence 3R*above the surface - the first such detection in a T Tauri star.


Abstract Copyright: 2008 The Authors. Journal compilation © 2008 RAS

Journal keyword(s): stars: individual: TWA 6 - stars: late-type - stars: magnetic fields - stars: pre-main-sequence - stars: rotation - stars: spots

Simbad objects: 19

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2020.02.17-03:33:54

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