Főoldal     Alapinformációk     To Survive in the Universe    
Inhabited Sky
    News@Sky     Asztrofotók     Kollekció     Fórum     Blog New!     GYIK     Sajtó     Bejelentkezés  

HD 4298


Tartalom

Képek

Kép feltöltése

DSS Images   Other Images


Kapcsolódó cikkek

Spectral classifications in the near infrared of stars with composite spectra. II. Study of a sample of 180 stars
A sample of 180 supposedly composite-spectrum stars has been studied onthe basis of spectra obtained in the near infrared (8370-8780 Angstroms)at a dispersion of 33 Anstroms/mm. The objective was to study the coolercomponents of the systems. Of our sample, 120 are true compositespectra, 35 are hot spectra of types B, F and 25 are Am stars. We find astrong concentration of the cooler components of the composite spectraaround G8III. In view of the difficulty of classifying compositespectra, because of the super position of an early type dwarf and a latetype giant or supergiant spectrum, we have made several tests to controlthe classification based upon the infrared region. Since all tests gavepositive results, we conclude that our classifications can be consideredas being both reliable and homogeneous. Table \ref{tab1} is alsoavailable electronically at the CDS via anonymous ftp 130.79.128.5 orhttp://cdsweb.u-strasbg.fr/Abstracts.html} Based upon observationscarried out at Observatoire de Haute-Provence (CNRS).

Cluster population incompleteness bias and the value of H(0) from the Tully-Fisher B0(T) relation
Data on the Virgo cluster and ten more distant clusters are the basis ofan evaluation of the influence of the cluster population incompletenessbias on the B-band Tully-Fisher relation. The data are well fitted by atheoretical curve that is obtained for a Hubble constant value of 72 +or - 5 km/sec per Mpc in the de Vaucouleurs local scale, confirming theconstant's previous determination in light of a study of the Malmquistbias for field galaxies. The true value for the Hubble constant isconcluded to lie within the 50-75 range, depending on the primarycalibration.

Új cikk hozzáadása


Kapcsolódó hivatkozások

  • - (nincs kapcsolódó hivatkozás) -
Új link hozzáadása


Besorolás csoportokba:


Pozíciós és asztrometriai adatok

Csillagkép:Androméda
Rektaszcenzió:00h45m37.37s
Deklináció:+30°20'10.7"
Vizuális fényesség:7.801
Távolság:212.314 parszek
RA sajátmozgás:19
Dec sajátmozgás:-16
B-T magnitude:8.131
V-T magnitude:7.829

Katalógusok és elnevezések:
Megfelelő nevek   (Edit)
HD 1989HD 4298
TYCHO-2 2000TYC 2276-269-1
USNO-A2.0USNO-A2 1200-00327300
HIPHIP 3569

→ További katalógusok és elnevezések lekérése VizieR-ből