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)

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 3 σ 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.