The Sun is currently in the main sequence phase of its life cycle, where it fuses hydrogen into helium in its core. Based on current scientific understanding, it is estimated that the Sun has about 5 billion years left before it exhausts its hydrogen fuel and undergoes significant changes.
In approximately 5 billion years, the Sun will start to run out of hydrogen in its core. As a result, it will begin to expand into a red giant, swelling in size and becoming much brighter. During this phase, it is predicted that the Sun will engulf and destroy the inner planets of our solar system, including Mercury, Venus, and possibly Earth.
After the red giant phase, the Sun will shed its outer layers, creating a planetary nebula, and leaving behind a dense, hot core known as a white dwarf. This white dwarf will gradually cool down over an extremely long period of time, eventually becoming a cold black dwarf.
As for the solar system itself, it is expected to remain relatively stable during the Sun's evolution. However, the gravitational interactions between the Sun and other celestial bodies could cause some minor changes in the orbits of planets over very long timescales. Nevertheless, it is unlikely that any significant disruptions will occur within the next few billion years.
It's worth noting that scientific understanding and predictions can evolve as new research and observations emerge. Therefore, these estimates are based on our current knowledge of stellar evolution and may be subject to revision in the future.