RE "I'm pretty sure it would expand and go supernova "
Expand yes. Supernova NO. Our sun is too small to fuse the heavy elements that are required to cause a supernova. I forget which elements bigger than helium can be fused by a star the size of our sun, but eventually it'll just burn out and be a dense cinder.
IIRC, it's Hydrogen to Helium.
Helium to Carbon and Oxygen.
Carbon and Oxygen to Iron.
Iron is the absolute end.
1.44 solar masses is the Chandrasekhar limit. Below that is too little mass to generate a supernova.