SIMBAD references

We present a surface abundance Doppler image of singly-ionized calcium for the Bp star ε UMa based on high signal-to-noise CCD spectra. This map shows striking similarities to that of oxygen (Rice et al., 1997A&A...326..988R) and perhaps iron (Rice & Wehlau, 1990A&A...233..503R). The Ca II 866.2nm line has allowed us to obtain a detailed surface abundance map of calcium for ε UMa. The calcium abundance map has been used to locate the position of the positive magnetic pole on ε UMa at a longitude of 350.8 deg and a latitude of 25.8 deg. Calcium is distributed in a ring along the magnetic equator, along which the abundance is [Ca/H]=-5, which is close to a normal population I value. This represents an enhancement with respect to other regions by a factor of ∼10³. A secondary feature is present with [Ca/H]=-6.5. A chemically differentiated stellar wind is proposed as the main mechanism for generating the surface abundance distribution of calcium.