|   | 
				
					
	
		  | 
	 
	
		| Paper: | 
		18O and the Origins of HdC and R CrB Stars | 
	 
	
		| Volume: | 
		391, Hydrogen-Deficient Stars | 
	 
	
		| Page: | 
		51 | 
	 
	
		| Authors: | 
		Geballe, T.R.; Clayton, G.C.; Asplund, M.; Herwig, F.; Fryer, C. | 
	 
	
	
		| Abstract: | 
		We have detected enormously enhanced 18O and correspondingly small values of 16O/18O in many hydrogen-deficient carbon (HdC) stars and R Coronae Borealis (R CrB) stars. The similar ratios suggest a common origin for the two types of stars. Of the two leading candidates for the origin of R CrB stars, white dwarf mergers and final helium flashes, the former appears more likely to produce this and other observed isotopic anomalies. | 
	 
	
		| 
			
			
		 | 
	 
	
		  | 
	 
 
					 
				 | 
				  |