Judging from the size diagram, I'm going to estimate it's 1:100th the size of the sun overall. Would we even feel it's warmth?
Mass and luminosity are more important than physical size, though size is a small component of luminosity. Luminosity is mostly related to temperature, which is dependent on the mass and evolution if it is a main sequence star.
Anyway, the Sun is 1000 times the mass of Jupiter, which would make for a pretty dim red star even if fusion could be initiated, and Jupiter is pretty far away, so the effect will be small. I don't have the equation for luminosity and its relationship with mass, evolution, temperature, etc., but even a few degrees will wreck the biosphere.


 
						 
 
		 
    
	 
 
		
 
 
		 
 
		

 
 
		 The Bible may not be "intended" to cause damage originally, but it is wielded as a weapon and, too often, DOES INTEND to do even more than just cause damage and harm people, because it is pretended to contain the whole power of a supreme god (and I am obviously not talking about porn or exotic dancing) to annihilate people.
 The Bible may not be "intended" to cause damage originally, but it is wielded as a weapon and, too often, DOES INTEND to do even more than just cause damage and harm people, because it is pretended to contain the whole power of a supreme god (and I am obviously not talking about porn or exotic dancing) to annihilate people. 
 