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HD 7748


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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.

GPM - compiled catalogue of absolute proper motions of stars in selected areas of sky with galaxies.
Not Available

GPM1 - a catalog of absolute proper motions of stars with respect to galaxies
The description of the first version of the General Compiled Catalogueof Absolute Proper Motions (GPM1) for a sample of HIPPARCOS stars,derived with respect to galaxies within the plan called Catalogue ofFaint Stars (KSZ, Deutch 1952), is presented. The principal aim of theGPM1 construction was to provide absolute proper motions of stars todetermine the rotation of the HIPPARCOS system. The GPM1 cataloguecontains 977 HIPPARCOS Input Catalogue stars with V magnitudes $5^m -11^m in 180 fields north of -25 degrees of declination. The accuracy ofthe proper motions is 8 mas/yr (milliarcseconds per year). Comparison ofproper motions of GPM1 with those of the PPM and ACRS was performed andanalyzed with respect to systematic errors caused by spurious rotationof the FK5 system. The standard errors show that the rotation may bedetermined with an accuracy better than 1 mas/yr. Catalog is onlyavailable in electronic form at the CDS via anonymous ftpcdsarc.u-strasbg.fr or ftp 130.79.128.5.

First experience in automatic spectral classification related to the MEGA program
The results of automatic quantitative spectral classification of starsin field No. 10 (alpha-1950 = 1 h 18 m, delta-1950 = + 3 deg 13 min) ofthe MEGA program are presented. Some tentative stellar-statisticalresults are discussed.

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Osservazione e dati astrometrici

Costellazione:Pesci
Ascensione retta:01h17m20.30s
Declinazione:+04°23'31.1"
Magnitudine apparente:8.396
Distanza:97.561 parsec
Moto proprio RA:-19.6
Moto proprio Dec:-3.9
B-T magnitude:8.902
V-T magnitude:8.438

Cataloghi e designazioni:
Nomi esatti
HD 1989HD 7748
TYCHO-2 2000TYC 23-975-1
USNO-A2.0USNO-A2 0900-00302629
HIPHIP 6018

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