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		| Paper: | 
		V471 Tauri: Examining Eclipse Timing Variations with two   Independent Clocks | 
	 
	
		| Volume: | 
		509, 20th European Workshop on White Dwarfs (EuroWD16) | 
	 
	
		| Page: | 
		571 | 
	 
	
		| Authors: | 
		Vanderbosch, Z. P.; Clemens, J. C.; Dunlap, B. H.; Winget, D. E. | 
	 
	
	
		| Abstract: | 
		Eclipse timing variations (ETVs) in binary systems can result from a plethora of potential mechanisms, one of which is the interaction of an unseen third body causing a periodic wobble in the system's barycenter.  ETVs in the V471 Tauri dK+WD binary system have historically been attributed to such a cause.  Using the orbital period of the system (∼12.5-hr) and the spin period (∼9.25-min) of the WD as two independent clocks, we show that a third body interpretation of the ETVs cannot adequately explain the nature of this system.  A wobbling barycenter would introduce variations of equal magnitude to both the eclipse timing and the spin period O-C diagrams.  We present O-C diagrams for both clocks using photometric data spanning several years, noting a relatively flat line for the spin-period O-C.  We then argue for alternative mechanisms causing ETVs, namely the Applegate effect. | 
	 
	
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