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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.
| Proper motion and photographic photometry of R Leonis Minoris (the maser source IRC+30215).
The position, absolute proper motion (Table 3), photograhic photometry(Table 1) of the long period variable R LMi (the maser source IRC+30215)obtained using normal astrograph plates are given in the paper. Theepochs differ by 24.92 years. The r.m.s. errors of the co-ordinates aresigma(RA) = 0.008 s, sigma (Dec) = 0.10", those for proper motions aresigma (mu-RA cos dec) = 0.0073", sigma (mu-dec) = 0.0050". Two stars inthe region of R LMi have been suspected in variability (Table 1).
| UBV photometry of stars whose positions are accurately known. III
UBV photometric observations of 417 stars at BD declination 35-49 degfrom the NPZT(74) catalog of Yasuda et al. (1982) and the AGK3R catalogof Corben (1978), obtained with the 40-cm Cassegrain reflector atKvistaberg Observatory during 1984-1985, are reported. The data arepresented in tables, and the mean errors per observation are given as0.016 mag in V, 0.011 mag in B-V, 0.012 mag in U-B for U less than 10,and 0.026 mag in U-B for U greater than 10.
| New optical positions and proper motions of late type stars associated with SiO masers
The 33 cm astrograph of the Bordeaux Observatory has been used to derivewith respect to AGK3 reference stars, accurate positions of late typevariable stars variable stars associated with strong SiO maser emission.It is suggested that selected maser stars can be used to link theHIPPARCOS system and the VLBI extragalactic reference frame. The propermotions of the program (SiO) and reference stars are derived and, forthe program stars, are compared to the McCormick catalog of propermotions.
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Osservazione e dati astrometrici
| Costellazione: | Leone Minore |
| Ascensione retta: | 09h44m45.14s |
| Declinazione: | +34°58'16.0" |
| Magnitudine apparente: | 8.637 |
| Distanza: | 162.338 parsec |
| Moto proprio RA: | -22.9 |
| Moto proprio Dec: | -13.9 |
| B-T magnitude: | 8.982 |
| V-T magnitude: | 8.666 |
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