Principal     Comenzar     To Survive in the Universe    
Inhabited Sky
    News@Sky     Astrofotografía     La Colección     Foro     Blog New!     FAQ     Prensa     Login  

HD 184844


Contenidos

Imágenes

Subir su imagen

DSS Images   Other Images


Artículos relacionados

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.

The chemical evolution of the solar neighborhood. I - A bias-free reduction technique and data sample
The possible ways of measuring the age-metallicity relation for thegalactic disk in the neighborhood of the sun are discussed. It is shownthat the use of a field star sample chosen on the basis of effectivetemperature introduces a bias which results in a monotonic increase inthe metal abundance of the disk with time. However, if theage-metallicity relation for the disk can be shown to satisfy certaincriteria, the bias introduced in such a sample can be neglected: thegalactic disk apparently satisfies the criteria. It is concluded that asample analyzed through the use of uvby and H(beta) photometry inconjunction with a self-consistent set of theoretical isochronesprovides the least biased, most accurate estimate of the age-metallicityrelation for the disk.

Enviar un nuevo artículo


Enlaces relacionados

  • - No se han encontrado enlaces -
En viar un nuevo enlace


Miembro de los siguientes grupos:


Datos observacionales y astrométricos

Constelación:Telescopio
Ascensión Recta:19h39m18.65s
Declinación:-56°18'49.8"
Magnitud Aparente:8.25
Distancia:194.553 parsecs
Movimiento Propio en Ascensión Recta:21
Movimiento Propio en Declinación:-20.8
B-T magnitude:8.574
V-T magnitude:8.277

Catálogos y designaciones:
Nombres Propios   (Edit)
HD 1989HD 184844
TYCHO-2 2000TYC 8782-410-1
USNO-A2.0USNO-A2 0300-35975040
HIPHIP 96677

→ Solicitar más catálogos y designaciones a VizieR