måndag 21 mars 2011

Our Sun Twin?

Anna Önehag from Sweden, and her team has found our solar twin? Unlike our Sun the twin belongs to Messier 67 group. It may be that our Sun was born in M67 4,5 bilj. years ago, but has wandered away reports Populär Astronomi.

M67-1194, an unusually Sun-like solar twin in M67

Anna Önehag (t h) and Andreas Korn.

New video of a Sun burst.

Results. We find M67-1194 to have stellar parameters indistinguishable from the solar values, with the exception of the overall metallicity which is slightly super-solar ([Fe/H] = 0.023 ± 0.015). An age determination based on evolutionary tracks yields 4.2 ± 1.6 Gyr. Most surprisingly, we find the chemical abundance pattern to closely resemble the solar one, in contrast to most known solar twins in the solar neighbourhood.

Conclusions. We confirm the solar-twin nature of M67-1194, the first solar twin known to belong to a stellar association. This fact allows us to put some constraints on the physical reasons for the seemingly systematic departure of M67-1194 and the Sun from most known solar twins regarding chemical composition. We find that radiative dust cleansing by nearby luminous stars may be the explanation for the peculiar composition of both the Sun and M67-1194, but alternative explanations are also possible. The chemical similarity between the Sun and M67-1194 also suggests that the Sun once formed in a cluster like M67.

So we are entangled!

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