Subject: Why does the earth's orbit size not increase?

It's known to all of us that fusion occours in the sun to fuse hydrogen to 
produce heavier atoms. The mass defect(dm) is released as energy according 
to 
Einstein's formula E=mc2. Gravitational pull between Earth and the Sun is 
measured by Newton's formula F=G m1 m2 /r2 . As the Sun burns out the mass 
of 
the Sun decreases then shouldn't the Gravitational pull between the Sun 
and the 
Earth decrease. This would further result in the elongation of the orbit 
of the 
Earth. Why is it the observation contrary to this? Please explain why this 
does 
not happen?
 

Re: Why does the earth's orbit size not increase?