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DY/DZ from fine structure in the Main Sequence based on Hipparcos parallaxes

B. E. J. Pagel·L. Portinari
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Abstract

The slope Delta Y/Delta Z is a quantity of interest in relation to stellar evolution, the initial mass function and the determination of the primordial helium abundance. In this paper we estimate Delta Y/Delta Z from fine structure in the Main Sequence of nearby stars from Hipparcos data for stars with Z \leq Zsun and find a value of about 3, which is consistent with what has been found in extragalactic H II regions and with stellar models for suitable upper limits to the initial masses of supernovae according to the IMF slope adopted.

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B. E. J. Pagel, L. Portinari. 1997-11-27. DY/DZ from fine structure in the Main Sequence based on Hipparcos parallaxes. https://doi.org/10.1046/j.1365-8711.1998.01637.x

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