Further to my earlier Comments about Gas Giants ( which are mostly Hydrogen ).
There is a sort of "progression" in increasing Mass - from Gas Giants to Brown Dwarfs, to Stars, to Giant Stars , to Supergiant Stars.
Beyond a certain Mass - you get a Brown Dwarf, which emits a lot of light in the Infra-Red, a sort of "Nearly Star".
Masses beyond that - it gets hot enough and the core pressure gets high enough - Lithium and Deuterium wil Fuse, giving you a fairly short-lived "Mini Star".
After they are fused - it starts to cool.
Masses beyond that - the Hydrogen ( mono-hydrogen ) starts to Fuse, and as it is nearly ALL Hydrogen - you get a Star. Fusing Hydrogen into Helium. How big a Star, how hot and for how long - depends on how much Mass of Hydrogen, and how "young".
Early on - Hydrogen fuses rapidly, you get a Blue-White or White Star - later it gets a little cooler as Hydrogen Fuses more slowly, you get Yellow, then Orange, then Red Star, then it dies. Nearly every time when it dies ( Hydrogen has been used up ) you get a Nova type event.
Very Big - and you get a Giant Star - Fuses Hydrogen hotter and faster, but for less time - they end with Supernova Explosions.
Even Bigger ( more Massive ) - and you get a Supergiant Star - Fuses Hydrogen even hotter and faster, but for much less time - very big Supernova Explosion at end.
All Stars go from Blue-White, through White, Yeallow, Orange, to Red.
SMALL Stars can die fairly quietly - with a simple expansion ( like our sun will ).
Smallish Stars go out with a small Bang - Nova - leaving behind a White Dwarf ( Nasty hot Radiation ) and a cloud of debris.
Medium Stars or Big Stars go out with a bigger bang - Supernova - leaving behind a Neutron Star ( where the Mass of the remnant compresses and strips the Atoms to Neutrons ) - VERY Nasty X-Ray and Gamma Ray Radiation, Radio Emissions. Also - a largish Nebula cloud of debris - which may glow for a while.
Very Big Stars ( Supergiants ) go out with very big Supernovas - leaving behind a Black Hole ( the remnant gets so compressed it goes beyond the Limit ). There is also a lasrge Nebula of debris - often hot, but cooling.
Giant Stars and Supergiants have such a high pressure and temperature in their Core that they do not just Fuse Hydrogen -
When the Hydrogen is getting low ( converted to Helium ), they start to Fuse Helium to Nitrogen 14, Oxygen 15, Carbon 12, Nitrogen 12, or Oxygen 16 ( depending on Temperature and Pressure ).
Depending on Temperature and Pressure, and the availability of additional Helium - they can then follow the Fusion sequence -
Oxygen 16 and Helium to Neon 20
Neon 20 plus Helium to Magnesium 24
Magnesium 24 and Helium to Silicon 28
Silicon 28 and Helium to Sulphur 32
Sulphur 32 and Helium to Argon 36
Argon 36 and Helium to Calcium 40
Calcium 40 and Helium to Titanium 44
Titanium 44 and Helium to Chromium 48
Chromium 48 and Helium to Iron 52
Iron 52 and Helium to Nickel 56.
Then THE END.
If the Star has enough Mass and Material, it can follow through this entire sequence.
The last Fusion Reactions which form Iron and Nickel use up nearly all of the available Heat Energy in the Star, and the core will collapse - whilst the outer "shells" will be ejected in a massive explosion, a very big Supernova - which will throw all of the material outwards to form a Nebula.
This Nebula will usually be quite rich in Iron and Nickel - the materials which make-up Planet Cores and some Asteroids. It will also contain some of the other elements as well.
The Universe started out extremely rich in Hydrogen - in fact it was NOTHING ELSE.
The earliest Stars were nearly all Giant and Supergiant Stars ( annoyingly they are caled Generation III Stars ). All of these ( except any tiny ones ) are dead and gone - aged to Death, and Exploded.
THEY created all of the Elements in the Sequence above.
Some of the heavier Elements were created during the intense pressures generated ( for tiny periods of time ), by Supernovas. Others were created by Bombardment of Atoms by Protons, Neutrons and Electrons - both inside Stars and outside of them.
The next "Generation" of Stars are annoying called Generation II Stars - apart from some small ones, they are mostly gone as well. Large Stars, Giant Stars and Supergiant Stars in that "Generation" helped in creating more of the Elements heavier than Hydrogen.
Fortunately - as Elements like Carbon, Hydrogen, Oxygen, Nitrogen, Calcium, Phosphorous, Potassium are essential to our kind of life - both Plants and Animals.
Our Sun - and all of the Giant Stars and Supergiant Stars in our Galaxy are all in the third "Generation" of Stars - annoyingly called Generation I Stars.
So, we all benefit from the creation of a wide range of elements, both directly in Stellar Fusion - and indirectly, by external bombardment of elements by Electrons, Protons and Neutrons.
In fact - some Elements are only produced in this way. Bombardment by Protons of Carbon and Oxygen created most of the Lithium, Boron and Barium in the Universe - in fact Boron can only be created in this way.
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