|   | 
				
					
	
		  | 
	 
	
		| Paper: | 
		Near-IR Sizes of Circumbinary Disks | 
	 
	
		| Volume: | 
		487, Resolving The Future Of Astronomy With Long-Baseline Interferometry | 
	 
	
		| Page: | 
		353 | 
	 
	
		| Authors: | 
		Rajagopal, J.; Ridgway, S.; Hinkle, K. | 
	 
	
	
		| Abstract: | 
		We report the diameters in the near-IR of  disks around post-AGB binaries, measured using the CHARA array.  These are among the first measurements of these objects.  Various characteristics of these systems, including  the large IR excess and refractory-deficient stellar photospheres, have been linked to the possible existence  of stable Keplerian dust disks, probably  formed during the evolution of the binary pair. These systems are  also of interest as bright precursors of Planetary Nebulae. Our sample includes confirmed post-AGB binaries  as well as RV Tauri stars that have previously been included in the same class (as hosting circumbinary disks).   We used long (200 m) baselines to determine the stellar contribution to the coherent flux, thereby removing  a common source of large uncertainty in the disk sizes.  For the post-AGB stars, the disk sizes are consistent  with “wall” models, similar to the Herbig Ae/Be disks in many aspects.  The data provides the first direct  measurements of disk sizes and are the first step to further development of this type of model.  For the RV  Tauris, the sizes are smaller and consistent with simple shell models, hinting that these may have a   different morphology. | 
	 
	
		| 
			
			
		 | 
	 
	
		  | 
	 
 
					 
				 | 
				  |