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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.
| Optical polarization of stars of galactic latitudes b-45 degres.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976A&AS...23..125S&db_key=AST
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Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Tukan |
| Sað Açýklýk: | 00h17m47.15s |
| Yükselim: | -66°21'32.1" |
| Görünürdeki Parlaklýk: | 7.789 |
| Uzaklýk: | 77.399 parsek |
| özdevim Sað Açýklýk: | 64.8 |
| özdevim Yükselim: | -4.8 |
| B-T magnitude: | 8.745 |
| V-T magnitude: | 7.868 |
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