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Published online by Cambridge University Press: 12 April 2016
The occurrence of emission lines in high resolution blue spectra of four extreme helium stars is reported. This phenomenon is most apparent in the case of BD−9°4395 which displays emissions in He I, λ 3889 Å, C II, λ 4267 Å and in the C II multiplet No. 1 (λ 4740 Å). The latter is also present in LSE 78 and found to be variable. The C II emission lines are regarded as evidence for extended moving envelopes around BD−9°4395 and LSE 78. A possible relation to the hot R CrB star V348 Sgr is discussed.
HD 160641 and LSS 5121 show unidentified emission lines (λλ4485.6 Å, 4504.0 Å) which are also observed in some Of stars. No emission lines were found in the blue spectra of 12 extreme helium stars.