Cool Stars 14 - Submitted Abstract # 194
This version created on 05 October 2006

Mapping the total spot coverage at the surface of the K star, V378
Tau.


G. Hussain, University of St Andrews
S.H. Saar, SAO
J. Aufdenberg, NOAO
F. Ringwald, California State University, Fresno
C. Johns-Krull, Rice University

Doppler imaging is a powerful technique that has been used for twenty
years to map the spot distributions on the surfaces of active stars,
yet it underestimates the total spot coverage as it cannot detect
uniformly distributed spots or spots that are smaller than its
resolution limits - the resolution limit is usually greater than 3
degrees latitude.  TiO bands form at sub-photospheric temperatures in
G and K-type stars and thus provide an effective means of determining
both accurate starspot temperatures and the absolute spot coverage of
the stellar surface.  We carry out a spot mapping study on an
extremely active rapidly rotating K star, V378 Tau (Prot=0.262d,
vsini=96km/s, log LX/Lbol=-3.1);  combining both Doppler imaging and
TiO band fitting techniques to better ascertain the total spot
distribution on the surface of the star.  We explore how much spot
area can be "hidden" in small spots, below the resolution limits of
Doppler imaging.  We also investigate the spatial connection between
spots and active regions at different atmospheric levels by measuring
the strength of chromospheric activity indicators (e.g.  H alpha and
He I D3).

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