>>what I would wonder is ,whether the calculations prove anything , when the creation model is of a fully formed and functioning sun operating from day 4 appr 6,000 or so yr ago.<<

Does the Bible not say that the sun was created on the third day?

By your account the sun must be about 6,000 years old. If you are going to seriously take Genesis literally then the sun begins at that time.

What I said to you is clear and simple. Calculating the rate of consumption of the suns fuel and the amount of the product of that consumption the sun has been calculated at 4.5 billion years. This fact is accepted by all people who are not clinging to a self contradictory ancient myth of creation.