The surface temperature of the sun is about 6,000 degrees kelvin and has sunspots on the parts of the surface that are cooler. Many scientists trying to figure it out have observed the stability of the sun. Over there observations, it is concluded that the sun is one of the most stable stars scientists have studied. This stability does not last forever with stars because of the hydrogen fusion that is going on in the core of the star. Over the lifespan of a star, the core gets hotter and the size of the star grows exponentially. While the star grows, the luminosity it releases also grows.
The sun will get brighter and brighter as time goes on. This will not happen in our lifetime but over the next millions of years the sun’s light will be so bright that earth life will not be able to survive the intense heat. The sun will swell to the size that it will devour Mercury and Venus. This swelling would be like seeing a gigantic red giant rise every morning in the horizon that engulfs the sky instead of the small yellow sun we see today. This is however millions of years away and way beyond our lifetime. I highly doubt humans will even be around at that point due to a natural disaster that is imminent.
One interesting fact about the sun is the solar flares it projects in the atmosphere. The solar flares are enormous and could engulf the Earth. Solar flares are a large amount of energy projected from the sun due to sudden heating of the sun’s surface. This could question the sun’s stability over time but for now, the sun should be stable for tens of millions of years. The question now arises is will it become a white dwarf or will is supernova. I hope for a supernova but science proves that is will become a white dwarf. Which is the size of the earth and gives off light but extremely dim compared to the giant it once was.