Determination of the Abundance of Mercury from the Hg ii Line at 5677.10 Å in Late B-type Stars. III. HD 145389 (ϕ Her) and HD 186122 (46 Aql)

Abstract

The weak line of Hg ii located at 5677.10 Å is used to measure the mercury abundance in two HgMn stars, HD 145389 (ϕ Her) and HD 186122 (46 Aql). This line is detected at 3σ above the noise in the adjacent continuum in ϕ Her but not detected in 46 Aql. The synthesis of this line, using the current atomic parameters available in NIST, confirms a large overabundance of mercury in HD 143807, about 4.08 dex, which is actually smaller than the excess derived from the 3983.93 Å line in earlier studies. The synthesis of other lines close to the Hg ii line yields excesses in scandium (+1.9 dex), chromium (+1.0 dex) and yttrium (+3.34 dex) in ϕ Her.