Contingut
Imatges
Carregar la teva Imatge
DSS Images Other Images
Articles Relacionats
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.
| Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
| Secondary UVBY standards in the Harvard E-regions
Photoelectric uvby photometry for 201 stars which are already UBV (RI)cstandards is presented. The photoelectric data are closely tied to theCousins uvby standards and the stars should be suitable for use asfainter (7-11 mag) secondary standards.
| Young, high-velocity stars. I - Rotational velocities and a catalog of early-type stars at the South Galactic Pole
A catalog has been compiled of 305 early-type stars to F0 and 15thmagnitude in 218 sq deg at the South Galactic Pole. Stromgren photometryand medium- and high-resolution spectra for many of the catalog starshave been obtained. Radial velocities, H-beta line widths, Balmer jumps,and Ca II K line equivalent widths have been measured and tabulated.Rotational velocities were obtained for eight distant A stars and arefound to be typical of values for normal young main sequence stars.
| Young, high-velocity a stars. II - Misidentified, ejected, or unique?
The ages, abundances, and kinematics of a large number of early-typestars at the south Galactic pole are derived to examine the properties,augment the sample of high-velocity stars, and study hypothesesconcerning their origin. The results are compared to a group of normal Astars near the disk. It is suggested that at around 6.5 X 10 to the 8thyr ago, a major source of relatively low abundance hydrogen was accretedby the Galactic disk, forming young high-velocity stars that do notpartake of the age-abundance-kinematics relationships shown by otherstellar groupings.
| Four-colour observations of primary and secondary UVBY standards
Stromgren uvby photometry of primary standards and of the secondarystandards observed by Cousins (1985) in the E regions and by Twarog(1984) near the South Galactic Pole suggests that the Twarog c1 resultsare not on the standard system. Inconsistencies also occur in V and m1but it is not clear from which data these arise. Intercomparisonsdiscussed in this paper and by Eggen (1982, 1984) suggest thatsystematic errors, particularly in m1 and c1, could be widespread inSouthern Hemisphere uvby observations.
| UVBY secondary standards near the South Galactic Pole
uvby photometry of sufficient accuracy to qualify as secondary standarddata is presented for 36 stars of spectral type A5-G5 near the SouthGalactic Pole. The stars range in magnitude from V = 8.4 to 13.5. Twoanomalous stars, one an earlier misidentified and one a variable in V,are discussed.
|
Enviar un nou article
Enllaços Relacionats
- - No s'ha trobat enllaços -
Enviar un nou enllaç
Membre dels grups següents:
|
Dades d'Observació i Astrometria
| Constel·lació: | Sculptor |
| Ascensió Recta: | 01h08m41.25s |
| Declinació: | -34°18'49.1" |
| Magnitud Aparent: | 9.448 |
| Moviment propi RA: | 32.2 |
| Moviment propi Dec: | 10.2 |
| B-T magnitude: | 9.9 |
| V-T magnitude: | 9.486 |
Catàlegs i designacions:
|
INHABITED SKY
