The spectrum of the Cr star Epsilon Ursae Majoris.
Abstract
Fourteen coudé spectrograms (eight with dispersion 12.4 Å mm-1 and six 7 Å mm-1) of the Cr star ∈UMa (Ap) have been studied. The observations were made at the Haute Provence Observatory. The radial velocities of the various ions have been measured. The existence of Balmer progression in radial velocity is doubtful. The variability of some lines is in the opposite sense of K of Ca ii. Both a rough and a fine analysis have been made. The results of these analyses are compared and found to be in good agreement. The results of the fine analysis indicate a defect of Al, Si and Ca; Sc, Ti, Fe and Sr are normal, Mg and Ni are in slight excess. V, Cr and Mn are in excess by factors of 3, 12, 19; Y, Zr and Ba are in excess by factors of 9, 15, 30. Rare earths are in excess by factors ranging between 100 1000. These results are compared with the majority of the Cr-Eu-Sr stars.
- Publication:
-
Astrophysics and Space Science
- Pub Date:
- June 1981
- DOI:
- 10.1007/BF00648756
- Bibcode:
- 1981Ap&SS..77...41T
- Keywords:
-
- A Stars;
- Abundance;
- Metallic Stars;
- Stellar Spectra;
- Balmer Series;
- Chromium;
- Magnetic Stars;
- Radial Velocity;
- Spectral Line Width;
- Astronomy;
- Ap Stars:Chemical Composition;
- Ap Stars:Line Profiles;
- Ap Stars:Radial Velocities;
- Ap Stars:Spectra