Astron. Astrophys. 328, 602-605 (1997)

3. Observations and reductions

We observed the brightest stars in the Ursa Major Group located between 20 and 50 parsecs and visible at the period of observations. The observations were performed at the Observatoire de Haute Provence in France, with the 1.52m telescope and the Aurélie spectrograph equipped with a CCD detector. The resolving power was . During five nights in April 1995, we obtained more than one hundred spectra of the Ca II -K line at 3933Å for stars of the Ursa Major Group.

Standard reductions have been done with the MIDAS software, including the absolute wavelength calibration through fitting of narrow lines from a Thorium-Argon lamp. After co-adding individual spectra, we finally obtained spectra of the Ca II lines toward 26 stars. An example is given for HR 5062 in Fig 1.

Fig. 1. Spectrum of the Ca II -K line toward HR 5062. The stellar line is rotationally broadened ( =218 km s-1). No absorption is detected, neither interstellar nor circumstellar.

© European Southern Observatory (ESO) 1997

Online publication: March 26, 1998

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