shape of gas and shape of stars

How does the shape of the gas and shape of stars change as the galaxy ages? Does there exists any such formula which relates the shape/volume with the time?

• I think you need to formulate your question a bit more precise and detail more what you mean with 'shape of stars' and 'shape of gas'. Stars are always spheres in hydrostatic equilibrium -independent of the age the galaxy they reside in. And the gas... is somewhere between those... the shape and size and evolution of the ISM determined by the stars embedded inside it.... and it will shrink as stars are born from it and less is given back at the end of stellar life than consumed during their formation – planetmaker Nov 16 '20 at 7:55
• There are diagrams on the temperature and size of stars over time. I see no reason why a diagram of the shape couldn't be done, but I've never seen one. It should be relatively straight forward with young stars spinning faster and as a result, larger magnetic storms and a bit of an equatorial bulge and older stars, smaller storms and more circular. That would also depend on there being no external effect that might happen in a binary system either by the two stars in a close orbit, perhaps sharing material or one of the stars goes nova and the other gets a kick. – userLTK Nov 17 '20 at 16:18
• For example, this unusual star: space.com/13822-fastest-rotating-star-tarantula-nebula.html – userLTK Nov 17 '20 at 16:20
• @userLTK can you tell me like, for Mass of the halo as 5*(10^12), what would be the shape of the stars and gas, I think it does depend on the mass of halo, right? – space_nkc Nov 17 '20 at 17:57
• @space_nkc Stack Exchange prefers new questions be asked as separate questions, not in comments, but as a rule, the halo is just a gravitational byproduct of the rotating central body. Compared to the central body it would be extremely low mass and low density. (Galaxy dark matter halos being the exception to this rule). But I don't know how to calculate the specifics of the mass you gave me. I don't even know enough math to make a good guess. – userLTK Nov 17 '20 at 18:08