Inici     Començant     Sobreviure a l'Univers    
Inhabited Sky
    News@Sky     Astro Fotografia     La Col·lecció     Fòrum     Blog New!     FAQ     Premsa     Login  

HD 203488


Contingut

Imatges

Carregar la teva Imatge

DSS Images   Other Images


Articles Relacionats

Reddening estimation for halo red giants using UVBY photometry
Updated uvby observations for a larger sample of metal-deficient redgiants are presented and combined with a select sample of data from theliterature transformed to a common system. Using the reddening maps ofBurstein & Heiles (1982), new absolute magnitudes, distances,metallicities, and reddenings are derived for each star. Themetallicities are determined with a revised calibration of them1, (b-y) diagram based upon comparison to a complilation ofrecent spectrsoscopic abundances transformed to a common system. Thephotometric abundances agree very well with the spectroscopic; thedispersion among the residuals for 58 giants is +/- 0.16 dex. Thedereddened indices are used to show that for red giants with (Fe/H) lessthan -1.5, there is a well-defined relation in the c0,(b-y)0 diagram which exhibits only a weak dependence uponmetallicity. Use of the standard relations allows one to obtainreddening estimates for normal halo field giants and globular clustersin the appropriate metallicity range.

Astrometric and astrophysical discontinuities between the galactic old disk and halo stellar populations
Intermediate band, RI, and DDO photometry of the weak-lined stars in thefirst three volumes of the Michigan catalogs of spectral type arediscussed on the basis of luminosity and heavy element abundance. Theinterface between the old disk (Fe/H greater than -0.8 dex) and halo(Fe/H less than -1.2 dex) populations represents discontinuities in boththe stellar motions and the stellar physics. The CN strengths of bothevolved and unevolved halo stars decrease with decreasing temperature,in a mirror image of the increase with decreasing temperature for thedisk objects. The result for the halo giants has been attributed to deepmixing in the stellar atmospheres but the similar result for unevolveddwarfs indicates a difference in formation rather than in evolutionaryprocess of the two populations.

Catalogue of Metal-Deficient F-Stars to M-Stars - Part One - Stars Classified Spectroscopically - Supplement One
Not Available

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:Microscopium
Ascensió Recta:21h23m29.06s
Declinació:-32°47'16.6"
Magnitud Aparent:8.749
Distancia:392.157 parsecs
Moviment propi RA:-11.9
Moviment propi Dec:-11.4
B-T magnitude:9.798
V-T magnitude:8.836

Catàlegs i designacions:
Noms Propis   (Edit)
HD 1989HD 203488
TYCHO-2 2000TYC 7477-147-1
USNO-A2.0USNO-A2 0525-43242054
HIPHIP 105616

→ Sol·licitar més catàlegs i designacions de VizieR