HIGH-RESOLUTION SPECTROSCOPY OF THE R-CORONAE-BOREALIS STAR, V854 CENTAURI, DURING A DEEP MINIMUM

The R Coronae Borealis star V854 Cen was observed at minimum light (V approximately 15) at high spectral resolution (DELTAlambda=0.3 angstro m) from 5480 to 7070 angstrom. The spectrum consists of three componen ts: a continuum devoid of photospheric lines, a collection of sharp em ission lines of Sc II, Ti II, Y II, and Ba II, and broad emission line s of [O I], [N II], [S II], Halpha, Na D, and C2 Swan bands. A low res olution spectrum reveals additional lines of Ca II, [C I], and other s pecies. The sharp emission lines are considered to be chromospheric li nes. The broad lines with a full width of 400-500 km s - 1 come from a n extended region with a temperature of about 7000 K, but an electron density of 50 CM-3 or less. It is suggested that V854 Cen may be a bip olar nebula.