THE R-CORONAE-BOREALIS STARS - A FEW MERE FACTS

This review presents a selection of recent highlights of observations of R Coronae Borealis variables. Emphasis is placed on an abundance an alysis of a complete sample (18 stars) of the warm galactic RCBs. It i s shown that 14 of the 18 have very similar compositions: the iron mas s fraction ranges about a factor of 3 around the solar value (assuming C/He = 3%) but abundance ratios X/Fe for elements from Na to Ba show little variation. By contrast, the other 4 stars are deficient in iron but not in Na, Si, S and some other elements. With for example, (Si/F e] congruent-to Z the quartet is indeed 'peculiar'. One of the quartet , V854 Cen shows depletions of elements (other than CNO) similar to th e depletions seen in interstellar medium corresponding to average log n(H(tot)) = -1.5. Scenarios for creating RCB from normal single and do uble stars are summarised.