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The Tokyo PMC catalog 90-93: Catalog of positions of 6649 stars observed in 1990 through 1993 with Tokyo photoelectric meridian circle
The sixth annual catalog of the Tokyo Photoelectric Meridian Circle(PMC) is presented for 6649 stars which were observed at least two timesin January 1990 through March 1993. The mean positions of the starsobserved are given in the catalog at the corresponding mean epochs ofobservations of individual stars. The coordinates of the catalog arebased on the FK5 system, and referred to the equinox and equator ofJ2000.0. The mean local deviations of the observed positions from theFK5 catalog positions are constructed for the basic FK5 stars to comparewith those of the Tokyo PMC Catalog 89 and preliminary Hipparcos resultsof H30.
| The sun among the stars. I - A search for solar spectral analogs
A total of 77 solar-type stars in parts of the northern and southernskies have been photoelectrically scanned with 20-A resolution to findstars whose ultraviolet spectra (3640-4100 A) match that of the sun.Down to a V magnitude of 6.6 there seem to be only two: HR 7504 in theNorthern and HR 2290 in the Southern Hemisphere. No G2V star matches thesun; they all have weaker ultraviolet absorptions, most of them muchweaker. Stars that do match have B-V of 0.66 magnitude. The search showsthat G-type dwarfs are hotter than was thought before by manyresearchers, which has important consequences for metal abundancesderived with respect to the sun.
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Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Coban |
| Sað Açýklýk: | 14h12m52.86s |
| Yükselim: | +09°50'53.7" |
| Görünürdeki Parlaklýk: | 8.801 |
| Uzaklýk: | 179.856 parsek |
| özdevim Sað Açýklýk: | 5 |
| özdevim Yükselim: | -4.7 |
| B-T magnitude: | 10.379 |
| V-T magnitude: | 8.932 |
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