Tuesday, January 13, 2009

How Old Are The Stars?

... If the stars are born and die according to certain measurable factors, then analyzing those factors might help to design a "clock" that can be used to establish the age of any star.

Currently, according to scientists, we can accurately determine the age of our own Sun and no other star, because we can study it in great detail and ‘stardust’ from within the solar system can be brought to Earth and analyzed. As consensus viewpoints state, that makes the Sun’s age a fundamental model to calibrate readings from other stars and determine their ages.

Recently, NASA announced the Kepler Mission, built to explore extrasolar planetary systems with a Terrestrial Planet Finder (TPF) science package. One result that astronomers hope to gain from Kepler is ultraprecise brightness measurements of nearby solar-type stars that will enable an analysis of lowest-order stellar oscillations. This technique is known as "asteroseismology," the name derived from "helioseismology," or the study of wave propagation inside the Sun. Analysis of the oscillations are expected to reveal the state of the core of a star, which is the part that is thought to change most in structure as the star ages by fusing hydrogen into helium. By combining this information with other data like mass and chemical composition, it is thought possible to say how old the star is.

However, there is a problem. Present understanding of stellar aging relies on studying globular clusters of thousands of stars in the Milky Way. It was accepted that such stars were formed together and share the same composition and age. But the Hubble Space Telescope has shown that the stars have multiple populations of stars with different compositions.

Again, as the Electric Universe model points out, astronomers are taking a model of the Sun that has difficulty in explaining some of the most obvious features of the Sun and applying it to other stars. As the Electric Star hypothesis reveals: "there is no reason to attribute youth to one spectral type over another. We conclude that a star's location on the HR diagram only depends on its size and the electric current density it is presently experiencing...its age remains indeterminate regardless of its mass or spectral type. This is disquieting in the sense that we are now confronted by the knowledge that our own Sun's future is not as certain as is predicted by mainstream astronomy. We cannot know whether the Birkeland current presently powering our Sun will increase or decrease, nor how long it will be before it does so." We do not know the age of our own Sun! ...

via How Old Are The Stars? | Thunderbolts.

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