Home     Getting Started     To Survive in the Universe    
Inhabited Sky
    News@Sky     Astro Photo     The Collection     Forum     Blog New!     FAQ     Press     Login  

HD 159201


Contents

Images

Upload your image

DSS Images   Other Images


Related articles

Ca II H and K Photometry on the UVBY System. III. The Metallicity Calibration for the Red Giants
New photometry on the uvby Ca system is presented for over 300 stars.When combined with previous data, the sample is used to calibrate themetallicity dependence of the hk index for cooler, evolved stars. Themetallicity scale is based upon the standardized merger of spectroscopicabundances from 38 studies since 1983, providing an overlap of 122evolved stars with the photometric catalog. The hk index producesreliable abundances for stars in the [Fe/H] range from -0.8 to -3.4,losing sensitivity among cooler stars due to saturation effects athigher [Fe/H], as expected.

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.

Metal-Deficient Giants in the Galactic Field - Catalogue and Some Physical Parameters
Not Available

Submit a new article


Related links

  • - No Links Found -
Submit a new link


Member of following groups:


Observation and Astrometry data

Constellation:Autel
Right ascension:17h37m37.88s
Declination:-63°21'14.1"
Apparent magnitude:8.535
Distance:206.612 parsecs
Proper motion RA:2.3
Proper motion Dec:-66
B-T magnitude:9.63
V-T magnitude:8.626

Catalogs and designations:
Proper Names   (Edit)
HD 1989HD 159201
TYCHO-2 2000TYC 9057-1187-1
USNO-A2.0USNO-A2 0225-27984911
HIPHIP 86270

→ Request more catalogs and designations from VizieR