Image description: 
		 
			Our hypothetical planet is located at 2 
            AU. The main problem comes from the invisible part of light, called 
            ultra-violet which is very strong for this type of stars (spectral 
            type A). 
		 
			  
			Also, strong stellar winds could damage the atmosphere 
            and make UV rays even more powerful in their destruction. Maybe 
            some bacteria could live below planet's surface. Even if life starts 
            below the surface, the star will become red giant in next 1 billion 
            years, which is not enough for life to develop. 
		   
		This is the main 
            reason why O, B and A spectral type stars are excluded from the "search 
            for life". On this picture, we see the dawn at Sirius system. 
            Haze is due to the dust particles of this dead and burnt world. 
            
		 
		  
		Because of Sirius B, we couldn't move our hypothetical planet at 
            3 or 4 AU (better location) since Sirius B would disrupt this 
            planet's orbit and kick it out of the system.  |