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The chemical evolution of the solar neighborhood. I - A bias-free reduction technique and data sample
The possible ways of measuring the age-metallicity relation for thegalactic disk in the neighborhood of the sun are discussed. It is shownthat the use of a field star sample chosen on the basis of effectivetemperature introduces a bias which results in a monotonic increase inthe metal abundance of the disk with time. However, if theage-metallicity relation for the disk can be shown to satisfy certaincriteria, the bias introduced in such a sample can be neglected: thegalactic disk apparently satisfies the criteria. It is concluded that asample analyzed through the use of uvby and H(beta) photometry inconjunction with a self-consistent set of theoretical isochronesprovides the least biased, most accurate estimate of the age-metallicityrelation for the disk.
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Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Tukan |
| Sað Açýklýk: | 22h50m28.28s |
| Yükselim: | -59°31'31.9" |
| Görünürdeki Parlaklýk: | 7.458 |
| Uzaklýk: | 147.059 parsek |
| özdevim Sað Açýklýk: | 26 |
| özdevim Yükselim: | 3.8 |
| B-T magnitude: | 7.848 |
| V-T magnitude: | 7.491 |
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