Astronomy - Ch. 17: The Nature of Stars (24 of 37) Stellar Classification: Spectral Type

[@javierbiaggi3072]

Excelente and very clear. Thanks

[@MichelvanBiezen]

Glad it was helpful!

[@wastaggio]

It's interesting where do Calcium and Tittanium come from in a main sequence star, which is supposed to turn hydrogen into helium.

[@MichelvanBiezen]

All the elements beyond helium (available to other stars) come from type 2A supernova explosions during which all the elements on the periodic table are fused together. These then merge with nebula from which other stars are formed. Our Sun and our solar system are the remnants of such an explosion about 4.53 billion years ago. The atoms in your body were formed during that explosion.

[@wastaggio]

@@MichelvanBiezen So in the primordial Universe this method would be useless as the first nebulas that formed first stars did not contain such elements.

[@MichelvanBiezen]

That is correct. The older stars are almost entirely H and He. The newer stars like the Sun contain as much as 1% other elements.

[@trope584]

Thank you for your videos.

[@bartonpaullevenson3427]

I usually see tables of stellar properties starting with O3.