Here's why it fits the description:
* The Sun is Dying: The premise of the film is that the sun is dying and humanity is on the brink of extinction.
* Dangerous Mission: A crew of astronauts embarks on a desperate mission to reignite the sun using a nuclear bomb.
* High Stakes: The mission is incredibly dangerous, with the potential for catastrophic consequences.
Other movies that touch on a dangerous sun include:
* "The Day the Earth Stood Still" (1951 & 2008): While not the main focus, the alien visitor warns humanity of the dangers of their technology and the potential for destroying the sun.
* "Solaris" (1972 & 2002): A psychological sci-fi film where a space station orbiting a mysterious planet is affected by the planet's sun, leading to hallucinations and madness.
* "The Happening" (2008): A thriller where a mysterious environmental event causes people to commit suicide, possibly linked to changes in the sun's radiation.
If you're looking for a specific type of dangerous sun, like one causing solar flares or supernovas, let me know, and I can try to find a movie that fits your criteria.