User blog:HD 219134 g/HD 140283

HD 140283 is a Metal-Poor Subgiant Star From Constellation Libra. It's Has 190 light years away from our home planet, Earth.

Age
Because HD 140283 is neither on the main sequence nor a red giant, its early position in the Hertzsprung-Russell diagram has been interpreted with its data and theoretical models of stellar evolution based on quantum mechanics and the observations of processes in millions of stars to infer its apparent old age. For field stars (as opposed to stars in clusters), it is rare to know a star's luminosity, surface temperature, and composition precisely enough to get a well-constrained value for its age. Because of their relative scarcity, this is even rarer for a Population II star such as HD 140283

The proportions of elements in such metal-poor stars is modelled to tell us much of the earlier nucleosynthetic ("metals") yield, that is of elements other than hydrogen and helium from the supernovae of the locally-extinct Population III stars. Some of the latter may be visible in gravitational lensing in looking at deepest images such as the Hubble Ultra-Deep Field (i.e., their brief existence before their turning into supernovae). As with HD 122563, CS22892-0052, and CD -38° 245, HD 140283 has an excess of oxygen and the alpha elements relative to iron