Home     Evrende yaþayabilmek için    
Services
    Niçin Edinmelisiniz     En fazla Destek olanlar     Gökyüzü görüntüsü     Koleksiyon     Forum     Blog New!     SSS     Giriþ  
→ Adopt this star  

HD 46764


Ýçindekiler

Görüntüler

Resim Yükleyin

DSS Images   Other Images


Ýlgili Makaleler

Statistical Constraints for Astrometric Binaries with Nonlinear Motion
Useful constraints on the orbits and mass ratios of astrometric binariesin the Hipparcos catalog are derived from the measured proper motiondifferences of Hipparcos and Tycho-2 (Δμ), accelerations ofproper motions (μ˙), and second derivatives of proper motions(μ̈). It is shown how, in some cases, statistical bounds can beestimated for the masses of the secondary components. Two catalogs ofastrometric binaries are generated, one of binaries with significantproper motion differences and the other of binaries with significantaccelerations of their proper motions. Mathematical relations betweenthe astrometric observables Δμ, μ˙, and μ̈ andthe orbital elements are derived in the appendices. We find a remarkabledifference between the distribution of spectral types of stars withlarge accelerations but small proper motion differences and that ofstars with large proper motion differences but insignificantaccelerations. The spectral type distribution for the former sample ofbinaries is the same as the general distribution of all stars in theHipparcos catalog, whereas the latter sample is clearly dominated bysolar-type stars, with an obvious dearth of blue stars. We point outthat the latter set includes mostly binaries with long periods (longerthan about 6 yr).

UvbyHbeta_ photometry of main sequence A type stars.
We present Stroemgren uvby and Hbeta_ photometry for a set of575 northern main sequence A type stars, most of them belonging to theHipparcos Input Catalogue, with V from 5mag to 10mag and with knownradial velocities. These observations enlarge the catalogue we began tocompile some years ago to more than 1500 stars. Our catalogue includeskinematic and astrophysical data for each star. Our future goal is toperform an accurate analysis of the kinematical behaviour of these starsin the solar neighbourhood.

Radial-velocity measurements. V - Ground support of the HIPPARCOS satellite observation program
The paper presents data on 1070 radial velocity measurements of starsdistributed in 39 fields measuring 4 deg x 4 deg. The PPO series ofFehrenbach et al. (1987) and Duflot et al. (1990) is continued using theFehrenbach objective prism method.

Uvby-beta observations of 528 type B stars with V between the 8th and 9th magnitude
The paper presents uvby-beta measurements of 528 type B stars selectedfrom the SAO Catalog on the basis of two criteria: the spectral types inthe range B3-B5 and mV between the 8th and the 9th magnitude. Reddeningindependent (c1) values are estimated from the spectral classificationand compared to the observed values. No systematic trend with observed(b-y), H-beta, or spectral type appears to be present, but the range of(c1) residuals is surprisingly large. A rather large part of the starshas small beta values, smaller than for the BIa supergiants. Only twoare classified as O stars and most of them have the suffix e, ne, ornne. Most beta values for the O type stars are slightly above the upperlimit of 2.585 m.

Photoelectric photometry of selected SAO stars. III
Photometric observations of 131 SAO stars for use in calibrating dataobtained from the Near Infrared Photographic Sky Survey (NIPSS) arereported. The serial numbers of the primary NIPSS program fields inwhich the photometry was done are shown along with the approximateposition of each field and the number of stars observed in each field.The observations are listed, showing the SAO numbers of the programstars, their 1950 equatorial coordinates, the V magnitudes, and the(V-R) and (V-I) color indices. The mean errors in magnitudes and colorindices obtained by averaging deviations from the mean for each star areon the order of 0.02 mag.

Positions et Mouvements propres de 357 Etoiles de Repère de la Zone + 16° à + 18° pour l'époque et l'équinoxe 1950,0
Not Available

Yeni bir Makale Öner


Ýlgili Baðlantýlar

  • - Baðlantý Bulunamadý -
Yeni Bir Baðlantý Öner


sonraki gruplarýn üyesi:


Gözlemler ve gökölçümü verileri

Takýmyýldýz:Ikizler
Sað Açýklýk:06h35m51.51s
Yükselim:+17°12'00.1"
Görünürdeki Parlaklýk:7.466
Uzaklýk:189.753 parsek
özdevim Sað Açýklýk:-5.4
özdevim Yükselim:-15.7
B-T magnitude:7.484
V-T magnitude:7.468

Kataloglar ve belirtme:
Özgün isimleri
HD 1989HD 46764
TYCHO-2 2000TYC 1333-1602-1
USNO-A2.0USNO-A2 1050-03908487
HIPHIP 31503

→ VizieR 'den daha fazla katalog ve tanýmlama isteyin