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		| Paper: | Some Challenges to Massive Star Theories |  
		| Volume: | 465, Four Decades of Massive Star Research - A Scientific Meeting in Honor of Anthony J. Moffat |  
		| Page: | 227 |  
		| Authors: | Herrero, A.; García, M.; Urbaneja, M. A. |  
		| Abstract: | Extragalactic massive stars offer an excellent opportunity to test  massive star theories.
 We present the analysis of three massive extragalactic stars (two in IC 1613 and one in M33) that pose problems for our 
 models, both atmospheric and evolutionary models. We show that the difficulties are diverse and suggest possible ways out
 of the problems. Nevertheless, we conclude that, when examined in detail, we always find problems in the analyses, indicating that
 our current models are still insufficient to explain the stars as a whole. |  
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