|   | 
				
					
	
		  | 
	 
	
		| Paper: | 
		Doppler Imaging of Active Binary Stars | 
	 
	
		| Volume: | 
		318, Spectroscopically and Spatially Resolving the Components of Close Binary Stars | 
	 
	
		| Page: | 
		69 | 
	 
	
		| Authors: | 
		Strassmeier, K.G. | 
	 
	
	
		| Abstract: | 
		Binaries can be used as astrophysical laboratories to study a much larger range of parameters than nature would normally foresee for a single star. A good example is the evolution of the stellar magnetic field and its tracers. Solar analogy tells us that the surface starspot distribution, and its variation in time, is a fingerprint of the underlying dynamo process and its subsequent magnetic-field eruption as bipolar spots or spot groups. But is this also true for more massive and less massive stars, even for fully convective stars? I show how astronomers nowadays resolve a stellar surface by means of a tomographic imaging technique and recover the surface temperature distribution as a tracer of the magnetic field and, of course, also emphasize its limitations. The technique requires relatively high-resolution high-S/N spectra well sampled over a rotation period of the star and is, so far, mainly technology driven. Therefore, I will present also an update of future instrumentation for stellar-activity work. Finally, I focus the scientific discussion on three recent studies of active double-lined spectroscopic binaries as three representative proxies of stellar activity throughout the HR-diagram. | 
	 
	
		| 
			
			
		 | 
	 
	
		  | 
	 
 
					 
				 | 
				  |