Home     Baþlangýç     Evrende yaþayabilmek için    
Inhabited Sky
    News@Sky     Gökyüzü görüntüsü     Koleksiyon     Forum     Blog New!     SSS     Basýn     Giriþ  

HD 74686


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).

Frequency domain analysis of the light changes of the close eclipsing systems TX Ursae Majoris and S CANCRI
The aim of this paper has been to carry out an analysis of the lightcurves of two eclipsing systems TX UMa and S Cnc by Kopal's new methodof the analysis of the light curves of eclipsing systems in thefrequency domain. The elements of these systems are evaluated and theresults are discussed

MK classifications for F-and G-type stars. 3.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974AJ.....79..682H&db_key=AST

Computation of Elements of Eclipsing Binary Stars by High-Speed Computing Machines.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1962ApJS....7..351H&db_key=AST

Yeni bir Makale Öner


Ýlgili Baðlantýlar

  • - Baðlantý Bulunamadý -
Yeni Bir Baðlantý Öner


sonraki gruplarýn üyesi:


Gözlemler ve gökölçümü verileri

Takýmyýldýz:Su Yilani
Sað Açýklýk:08h45m23.32s
Yükselim:+00°11'51.9"
Görünürdeki Parlaklýk:6.564
Uzaklýk:110.254 parsek
özdevim Sað Açýklýk:-25.9
özdevim Yükselim:-5.9
B-T magnitude:7.842
V-T magnitude:6.67

Kataloglar ve belirtme:
Özgün isimleri   (Edit)
HD 1989HD 74686
TYCHO-2 2000TYC 212-933-1
USNO-A2.0USNO-A2 0900-06136802
HIPHIP 42957

→ VizieR 'den daha fazla katalog ve tanýmlama isteyin