What materials can a star produce before dying?

[Bandersnatch]

If it depends on the mass then is there a way to know some kind of "convective factor" or "mixing factor" of a star given it's mass, the higher the mass the more convective the star is and the more elements are present in the outer layer, or maybe it doesn't work this way ?

The point is, the convective layer in all but the least massive stars doesn't extent down towards the core until the star leaves the main sequence. There is no appreciable dredging-up of the fusion products until then. It's also worth noting that the eventually dredged up material is mostly helium and nitrogen. You don't get deep core materials in the ejecta until a supernova.
And the least massive stars with fully convective interiors never fuse anything heavier than helium, nor do they expel their material in any way apart from solar wind - a minuscule effect.

What are the 3/4 and 1/4 for ?

The 75 and 25% initial composition. In each gram, 3/4 is made of this and 1/4 of that.I have to say, this whole scooping of elements idea might be a bit of a stretch. Why would players want to fly around through AUs and AUs of space to scoop from around stars heavy elements, that even in a planetary nebula will constitute only a few percent fraction of the few thousand (at best!) atoms per cubic centimetre you can find there, and will not be terribly different from the composition of a regular cloud of gas in the interstellar space?
Why not make use of materials already compacted by gravity into asteroids instead?

Perhaps sticking to 'scooping hydrogen fuel' from stars and gas giants with some thingamajigar like you could in the old Elite games would be enough?

 

[Ranguna]

Yes there are a lot of star types so it would need to be quite a big database

No that I don't of it, maybe a database isn't even needed, I'll just use average data and then randomize the star's propriaties.. a lot.

I was just suggesting this as a way to get best use of your processor by not having it repeatedly do essentially the same calculation for similar star types.

My game has about 3,489,013,663 but the algorithms will only calculate one star, the star that the player is close to, and so as of yet there is no problem with the processor usage.

Find an 'average' range for a particular type of star and then when you create the star in-game just randomize the properties within this range. You could also weight some of the properties to vary more or less if the mass of the star is more or less than the average within that range.

Yeah that's probably what I'm going to do.

I have to say, this whole scooping of elements idea might be a bit of a stretch. Why would players want to fly around through AUs and AUs of space to scoop from around stars heavy elements, that even in a planetary nebula will constitute only a few percent fraction of the few thousand (at best!) atoms per cubic centimetre you can find there, and will not be terribly different from the composition of a regular cloud of gas in the interstellar space?
Why not make use of materials already compacted by gravity into asteroids instead?

Well the player isn't actualy going to fly around space, he can jump from one star to the other. Hmmm... mining asteroids, that's a good idea.

The 75 and 25% initial composition. In each gram, 3/4 is made of this and 1/4 of that.

Oh right, right

Perhaps sticking to 'scooping hydrogen fuel' from stars and gas giants with some thingamajigar like you could in the old Elite games would be enough?

Yeah, that's probably going to be the only use that the star is going to have, that and the ability to heat planets and to destroy them too.Final question, is there a way to know how much a star will grow once it leaves the main sequence ?

 

[Zeedr]

Hey, if you are calculating the star processes in such detail, why not go for broke and try and account for the doppler effect? Like if you land on an asteroid moving fast away from the star, it looks red, if you are on an asteroid heading straight for it, it looks more blue.

 

[Zeedr]

Yes there is, if a star's mass is large enough to start fusing helium nuclei, then it will become a red supergiant, and typically, the larger the mass of a main sequence star, the larger a red supergiant will be. If the star is unable to fuse helium, it becomes a red giant - but with an edge, instead of just continuing to exist in that form (as does a red supergiant) the burning gas on the outside start to drift away - you could make this into a cool effect btw - especially if two red giants are being phased into white dwarfs (the white hot centre left behind after a red giant phase) next to each other, their gravity will pull the gaseous matter into swirls, and the two dying stars will orbit each other, in a dance of death. Poetic. You can of course use computer models and simulations to adjust for exact sizes, and influences (gravitational effects etc.) but you said you just wanted a rough, rule of thumb type idea before.

 

[Ken G]

I would have asked if you mean by "fusing helium" the process that starts with helium, or ends with it, but you also appear to be confused about the difference between a red giant and a red supergiant, so I'm not sure if it is worth pursuing. We can agree that there are interesting possibilities to pursue in the end stages of the evolution of stars, depending on what kinds of processes the gamers wish to include.

 

[Stormbringer]

Is it possible to calculate how much Helium a star can produce when it reaches the end of the main-sequence, right before it starts burning Helium ( given if it has enough mass to do so) ?

And if it is possible then is it also possible to calculate how many materials a star can produce given it's mass ?

I'm kind of starting my journey into physics so forgive me if I write anything that might not be scientifically correct.
Thanks for reading.

depends on the star. Small stars like m dwarf/red dwarves burn all their hydrogen and have lifespans longer than the life of the universe so far; trillions of years in some cases. stars like our sun only burn about ten percent of their hydrogen before dying and thus have a relatively brief lifespan. that is because red dwarves mix their fuel via convection. if you could stir up a star like ours you could give it a new lease on life. Also about what someone said in the thread that heavy elements are only created by novae or supernovae events; while this is when the bulk of the synthesis of heavier elements occur there are significant amounts made before the nova period by a different synthesis mechanism.

So for your game mechanic algorythm you would need one for red dwarves and another for larger stars. Also in some cases uncommon synthesis processes can theoretically occur; like in binaries or multiple star systems with one partner a pulsar, neutron star, or white dwarf and the other a red super giant or blue super giant.