An internacional project “Lithium in magnetic Ap stars” has been run since 1996 with the purpose of creating an observational database allowing systematic studies of the abnormal occurence of lithium on the surface of cool Ap stars. The 2.6 m telescope at the Crimean Astrophysical Observatory, the ESO CAT, ESO 1.52 m telescope with FEROS, the Nordic Optical Telescope, and the 74″ telescope at Mount Stromlo were employed to collect observations at the regions of the lithium resonance lines $\lambda 6103$ and $\lambda 6708 \AA$.

Observations of the roAp-stars HD 83368, HD 60435 and HD 3980 revealed considerable periodical Doppler shifts of the line of lithium $\lambda 6708 \AA$ which can be explained by the presence of lithium spots on their surfaces. Conjunction with structures of the magnetic field is apparent.

A detailed study of the blend at $\lambda 6708 \AA$ in HD 101065 confirmed the anomalous overabundance of lithium amounting to 3.1 dex, as well as unusual isotopic ratio $^6{\rm Li}/^7 {\rm Li} \sim 0.3$.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We report the results of the spectral monitoring of the chemically peculiar (CP2) star HD 3980 in the Li I$\lambda 6708$ spectral region. High spectral resolution observations ($R=88000$) were carried out at Mount Stromlo Observatory with the 74-inch telescope and the echelle spectrograph. HD 3980 is a late type Ap SrCrEu star with strong double-wave photometric variations in the visible and in the near infrared. We estimated the effective temperature, surface gravity, mass, luminosity, and radius of this star. The monitoring of this star shows strong spectral variations, especially in the profile of Li I$\lambda 6707.8$. We studied the variations of the equivalent width and position of the Li I line as a function of the rotating phase and compared them with the magnetic field variations and light curves taken from the literature. The synchronism of the variations of the Li I line profile, light curve, and magnetic field strength can be explained in terms of the oblique magnetic rotator model. The strong variations of position and intensity of this line with the rotation phase enable us to consider this star as a new member of the intriguing group of “Li-spotted” CP stars.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html