Surface Distribution of Iron and Chromium on 84 UMa
Abstract
High resolution spectra of 84 UMa have been used to map the surface distributions of iron and chromium. The abundances of iron and chromium on the surface varied by a factor of 15. Iron is less abundant than in the solar atmophere, by about a factor of 0.6 in the maximum areas, while chromium is more abundant than in the sun, by about a factor of 600 in the minimum areas; the abundances are compared with those for three other CP stars previously studied. The best fit of the computed line profiles to the observed ones was obtained using a microturbulent velocity of 4 km s^-1; such broadening may be due to the Zeeman effect of an undetected magnetic field. Although the surface distributions show some regular structure, no symmetries similar to those found for other stars with dipolar magnetic fields are apparent. (SECTION: Stars)
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- February 1994
- DOI:
- 10.1086/133357
- Bibcode:
- 1994PASP..106..134R
- Keywords:
-
- Abundance;
- Chromium;
- Iron;
- Metallic Stars;
- Metallicity;
- Stellar Composition;
- Stellar Spectra;
- Doppler Effect;
- Stellar Magnetic Fields;
- Zeeman Effect;
- Astronomy;
- STARS: INDIVIDUAL: 84 URSAE MAJORIS;
- STARS: EMISSION-LINE