Ahh just a correction it's the Hertzsprung Russell diagram. https://en.m.wikipedia.org/wiki/Hertzsprung–Russell_diagram
Im definitely rusty on this. Sent from my iPhone On 30 Mar 2017, at 20:09, Stephen Cooke <stephen_coo...@hotmail.com<mailto:stephen_coo...@hotmail.com>> wrote: Yup I think helium content could play apart. I'm not sure how much gets mixed up to the surface. It's going back decades since I followed this stuff but if I remember right more normally I think they look at the size, mass and colour of the stars as in the Hershel Russell diagram to determine their age. But this is not the whole picture as we also have different generation of stars. I think stars in globular clusters for example are typically older generation stars so are typically off to the side of the diagram and also typically have higher concentrations of Hydrogen. Typically older generation stars have more "metals" in astrophysical terms "metals" are elements heavier than Helium. 1st generation stars are just made of hydrogen and helium and some Lithium that was formed in the Big Bang. Interestingly stars can actually burn the Lithium so the abundance of Lithium in stars can be less than expected. At least that is the normal explanation. Certainly helium content should help identify older generations of stars though along with amounts of other elements. It's very curious to think about the possible role of LENR especially if dusty plasmas are present in later generations. Even Nova on white dwarfs might show interesting signatures. It's an interesting idea I think. On 30 Mar 2017, at 19:34, Jed Rothwell <jedrothw...@gmail.com<mailto:jedrothw...@gmail.com>> wrote: <mix...@bigpond.com<mailto:mix...@bigpond.com>> wrote: I wonder how they know the age? From the make up of the gasses, I believe. Young stars have more hydrogen. I suppose if cold fusion is playing a role that method may not be accurate. - Jed
