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Effective temperature scale and bolometric corrections from 2MASS photometry We present a method to determine effective temperatures, angularsemi-diameters and bolometric corrections for population I and II FGKtype stars based on V and 2MASS IR photometry. Accurate calibration isaccomplished by using a sample of solar analogues, whose averagetemperature is assumed to be equal to the solar effective temperature of5777 K. By taking into account all possible sources of error we estimateassociated uncertainties to better than 1% in effective temperature andin the range 1.0-2.5% in angular semi-diameter for unreddened stars.Comparison of our new temperatures with other determinations extractedfrom the literature indicates, in general, remarkably good agreement.These results suggest that the effective temperaure scale of FGK starsis currently established with an accuracy better than 0.5%-1%. Theapplication of the method to a sample of 10 999 dwarfs in the Hipparcoscatalogue allows us to define temperature and bolometric correction (Kband) calibrations as a function of (V-K), [m/H] and log g. Bolometriccorrections in the V and K bands as a function of T_eff, [m/H] and log gare also given. We provide effective temperatures, angularsemi-diameters, radii and bolometric corrections in the V and K bandsfor the 10 999 FGK stars in our sample with the correspondinguncertainties.
| Photoelectric photometry of stars near the north Galactic pole. II UBV photometric observations of about 700 stars near the north Galacticpole, obtained using single-channel photometers on the 40-cm and 60-cmCassegrain telescopes at Kvistaberg Observatory (during 1976-1983) andthe Spanish International Observatory (during 1984), respectively, aspart of a program including the stars to be observed by the Hipparcosspacecraft, are reported. The data are presented in a series of tablesand briefly characterized.
| Further Studies of A-Stars and F-Stars in the Region of the North Galactic Pole - Part Four - a Catalogue of Uvbyr Photometry and Derived Quantities Not Available
| Further Studies of A-Stars and F-Stars in the Region of the North Galactic Pole - Part Three - a Catalogue of Star Names and Positions Not Available
| The optical polarization of Ton 1542 Ton 1542 has recently been identified (Lelievre and Vanderriest, 1976)as a quasar nucleus in an extended type I Seyfert galaxy. Polarimetry ofTon 1542 was carried out in total light at the Observatory of Lyon ontwo days with the following results: for April 12, 1975, p equals 2.9per cent plus or minus 0.6 per cent and theta equals 72 degrees plus orminus 2.8 degrees; for June 8, 1975, p equals 4.0 per cent plus or minus1.0 per cent and theta equals 35 degrees plus or minus 3.5 degrees. Forthe quasar nucleus, after subtraction of the galaxy component,polarization attains p equals 6.0 per cent plus or minus 1.6 per cent, aresult which can be explained by synchrotron emission from the nucleus.
| Studies of A and F stars in the region of the North galactic pole-I. Radial velocities and MK Classifications Not Available
| Interstellar reddening near the north galactic pole Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972PASP...84..497F&db_key=AST
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Takýmyýldýz: | Berenisin Saci |
Sað Açýklýk: | 13h22m54.22s |
Yükselim: | +17°46'32.9" |
Görünürdeki Parlaklýk: | 8.666 |
Uzaklýk: | 182.149 parsek |
özdevim Sað Açýklýk: | 9.1 |
özdevim Yükselim: | 1.1 |
B-T magnitude: | 8.963 |
V-T magnitude: | 8.691 |
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