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HD 141413


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Ca II H and K Filter Photometry on the UVBY System. II. The Catalog of Observations
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995AJ....109.2828T&db_key=AST

The Sirius supercluster in the FK5
Fifty-five stars in the FK5 or with PPM(H) quality proper motions arediscussed as members of the Sirius supercluster. The convergent point ofthe supercluster motion is (A, D) = (20.55h -38.1 deg) and the spacevelocity is V(T) = 18.6 + 0.005X km/s, where X is the radial distance ofthe members from the sun. The member stars indicate (Fe/H) Hyades -(Fe/H) Sirius = 0.18 dex from both photometric and spectroscopicevidence. The bulk of the supercluster members fall into two age groups,6.3 x 10 exp 8 and 10 exp 9 yr on the basis of models with convectiveovershoot. The available observations of chromospheric activity in Mg II(h and k) are quantized into three well-defined groups for both Siriussupercluster and Hyades cluster dwarfs. For 20 supercluster members withcluster parallax greater than 0.03 arcsec the ratio ofpi(cluster)/pi(trigonometric) = 0.95 +/- 0.20(sigma).

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:Guney Ucgeni
Sað Açýklýk:15h52m56.70s
Yükselim:-65°09'09.0"
Görünürdeki Parlaklýk:6.54
Uzaklýk:126.743 parsek
özdevim Sað Açýklýk:36.5
özdevim Yükselim:7.8
B-T magnitude:6.776
V-T magnitude:6.559

Kataloglar ve belirtme:
Özgün isimleri   (Edit)
HD 1989HD 141413
TYCHO-2 2000TYC 9031-1101-1
USNO-A2.0USNO-A2 0225-24037746
BSC 1991HR 5876
HIPHIP 77785

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