Cool Stars 14 - Submitted Abstract # 233
This version created on 05 October 2006

Active regions in a sample of late-type rapid rotator stars:
spectroscopic analysis


M. Magdalena Hernan-Obispo, Universidad Complutense de Madrid
Elisa de Castro, Universidad Complutense de Madrid
UCM - University of Florida Galvez M.Cruz
Manuel Cornide, Universidad Complutense de Madrid
David Montes, Universidad Complutense de Madrid

High-resolution spectral and temporal echelle observations of
late-type rapid rotator stars have been carried out along several runs
using:  SOFIN spectrograph at 2.56m Nordic Optical Telescope (NOT, La
Palma), FOCES spectrograph in 2.2m Telescope at Calar Alto Observatory
and SARG spectrograph at 3.58m Telescopio Nazionale Galileo (TNG, La
Palma).  The detailed analysis of spectra with high S/N can be use to
detect the presence of active regions in different layers:  spots on
photosphere, plages and prominences on chromosphere and flares.  In
essence we search temporal variations on equivalent width and profile
line asymmetry of different magnetic indicators (mainly Hα
(6562.9 A) and Hb (4861 A)).  Heliocentric radial velocity variations
have been also determined.  To study the radial velocity variations,
the correlation with line bisectors of cross-correlated photospheric
lines is calculated.  In this contribution the applied method and main
results are presented for BD+20  1790  .

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