|   | 
				
					
	
		  | 
	 
	
		| Paper: | 
		Recent Observations of Betelgeuse and New Instrumentation  at the ISI | 
	 
	
		| Volume: | 
		487, Resolving The Future Of Astronomy With Long-Baseline Interferometry | 
	 
	
		| Page: | 
		337 | 
	 
	
		| Authors: | 
		Lockwood, S.; Ravi, V.; Wishnow, E. H.; Fitelson, W.; Mallard, W.; Werthimer, D.; Mistry, H.; Townes, C. H. | 
	 
	
	
		| Abstract: | 
		The Infrared Spatial Interferometer (ISI) has been conducting mid-infrared observations of late-type stars for about 18 years.  A long-term set of diameter measurements of Betelgeuse at 
 11.15 μm shows pronounced changes in the stellar size over time.  These changes may arise from variations in the opacity of the environment immediately surrounding the star.  New 
 instrumentation is being developed to identify the composition and kinematics of the circumstellar environment of Betelgeuse, and of other late-type stars.  A digital spectrometer-correlator 
 is being built and tested that will enable visibility measurements on and off individual molecular spectral lines.  Results from testing the spectrometer system are presented. | 
	 
	
		| 
			
			
		 | 
	 
	
		  | 
	 
 
					 
				 | 
				  |