This paper presents elemental abundance analyzes of three sharp-lined B stars using spectrograms obtained with the 2.15-m telescope of the Complejo Astronomico El Leoncito (CASLEO) and a REOSC echelle spectrograph, which is on loan from the Institute Astrophysique de Liège, Belgium, and a TEK 1024 CCD. The cross disperser was a grating with 1200 lines mm-1. (See Paper I, Pintado & Adelman 1996, for additional details.)
Paper II (Adelman & Pintado 1997) found that the equivalent width
scale of these spectrograms for lines whose equivalent widths are 15 mÅ or
greater is marginally greater than those for Kitt Peak National Observatory
(KPNO) coudé feed CCD and Dominion Astrophysical Observatory (DAO) Reticon
spectrograms. Further the 
4500-5600 region for
Mercury-Manganese (HgMn) stars contains many unblended lines which are useful
for increasing the quality of abundance studies based on KPNO and DAO
spectrograms. This region contains a sufficient number of lines for high
quality abundance analyses. In this paper we study two HgMn stars and one
hotter somewhat similar star.
The bright Southern star HR 4487 (= HD 101189) is a member of NGC 3766 which is part of the Sco-Cen Association. Heck et al. (1987) suspected it is a long period photometric variable. Bidelman (1988) comments it is a remarkable Ap star that deserves detailed study.
Stickland & Weatherby (1984) found v sin i = 35 km s-1 for the HgMn Star 14 Hya (= HR 3500 = HD 75333). Adelman & Pyper (1979) obtained optical spectrophotometry.
Jugaku et al. (1961) performed an abundance analysis
of 3 Cen A (= HR 5210 = HD 120709) which is a hot nonmagnetic CP star,
probably related to the HgMn stars. Sargent & Jugaku (1961)
determined that
84% of its He is He3. Latter Sargent et al. (1969)
found it has a normal Ne abundance, weak He I lines, and normal C II lines.
It is not a member of the Scorpio-Centaurus OB Association
(Thompson et al. 1987). De Geus et al. (1989)
found 
K,
log g = 4.18 from Walraven photometry. Breger (1976) includes optical
spectrophotometry in the Hayes-Latham (1975) system. Recently
Castelli et al. (1997) derived the abundances using high dispersion IUE exposures.