Recently, I’ve been thinking about star and star system formation a lot.

The basics, I understand it, runs something like this.

1) A large cloud of gas, the remnants from previous stellar explosions, begins collapsing under its gravitational attraction.

2) Angular momentum spins faster compressing it into an accretion disk. In the disk denser clumps begin gathering and forming the seeds of planets.

3) Most of the cloud is pulled to the center forming a massive body whose center becomes more and more compressed raising the temperature.

4) When the temperature and pressure get high enough the star ignites and blows out the last vestiges of the cloud. Leaving a star and forming planets.

I have questions.

As the cloud compresses into a star but before fusion starts hoe dense does that gas get? Do we get atmospheres of pressure reaching from the core out to the orbital distances of the future planets? Would it be dense enough for aerodynamic forces? Do we potentially have dense enough gas that there is effectively an atmosphere between the soon to be star and it’s forming planets? Could electric charges build up in this massive cloud producing planet-sized or large lightning bolts?

When the fusion starts how fast is that process? Is it thousands or millions of years between ignition and having a star or is much shorter and explosive? What sort of pressure is generating in the remaining cloud as a blast wave that sweeps through the emerging star system?

Welcome to the late-night thoughts of a science fiction writer.