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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.
| Speckle interferometry of HIPPARCOS link stars. III
A third list of stars is presented which have been tested by speckleinterferometry for use in the Hubble Space Telescope link between theHipparcos astrometric reference frame and the extragalactic VLBIreference frame. Structural information on angular scales of 0.15-1.2arcsec for 34 Southern Hemisphere stars is reported from observationsmade with the Imperial College Speckle Interferometer mounted on theMount Stromlo 1.9-m telescope. Twenty-four percent of the stars (8 outof the 34) show evidence of multiplicity, in agreement with previousobservations in this program.
| A catalogue of QSOs and link stars for the HST link of the HIPPARCOS reference frame
A list of bright (less than 17 mag) southern QSOs and bright (less than11 mag) stars that may be suitable for the Hubble Space Telescope linkbetween the Hipparcos astrometric reference frame and the VLBIextragalactic frame is presented. The QSOs have been selected fromvarious lists of radio objects and identifications. The stars have beenselected from the Strasbourg (CDS) data base and from the PreliminarySecond Cape Photographic Catalog, and supplemented with stars measuredfrom the SERC IIIa-J Schmidt survey. These QSOs and stars have beenincluded in the Hipparcos and HST schedule of observations.
| Estimation of stellar intrinsic colours, distances and colour excesses based on the Stromgren and H-beta photometry of 804 B, A, and F stars in 10 Selected Areas
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1989A&AS...78..105F&db_key=AST
| Four-colour UVBY and H-beta photometry of all A and F stars brighter than MPG of about 11.0 mag in 4 Selected Areas at intermediate galactic latitudes
As a second part of an investigation of the distribution of interstellardust in the solar vicinity, uvby-beta photometry has been obtained for260 stars of spectral types A and F, and brighter than mpg of11.0 mag in four Kapteyn's Selected Areas. The observed areas are: SA95, SA 120, SA 168, and SA 200. They are centered at intermediategalactic latitudes, in the range from b of about -38 deg to -42 deg.From the observed (b-y) versus beta diagrams it can be seen that starsin SA 95 are strongly affected by reddening, while the other areas showvery little absorption.
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| Takýmyýldýz: | Celik Kalem |
| Sað Açýklýk: | 04h41m35.13s |
| Yükselim: | -43°00'34.4" |
| Görünürdeki Parlaklýk: | 9.394 |
| özdevim Sað Açýklýk: | 22.9 |
| özdevim Yükselim: | -42.4 |
| B-T magnitude: | 9.937 |
| V-T magnitude: | 9.439 |
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