whats the highest temperature the sun can get?

Question: whats the highest temperature the sun can get?
- Keywords:
  heat,
  sun,
  temperature
Asked by achelleabby to Ed, Hayley, Jason, Nathan, Sophie on 13 Mar 2013.
- Hayley Evers-King answered on 13 Mar 2013:
  
  On average the surface is around 5500 degrees, but sunspots can be as cool as 4000 degrees and the number of these can vary. In the core, it’s estimated that the sun is more than 15 million degrees! The general theory is that the sun is getting hotter over time (very slowly!) and in about a billion years it will be too hot for Earth to keep liquid water.

Question: whats the highest temperature the sun can get?