Главная     Выжить во Вселенной    
Services
    Why to Inhabit     Top Contributors     Астрофотография     Коллекция     Форум     Blog New!     Помощь     Войти  
→ Adopt this star  

HD 3378


Оглавление

Изображения

Загрузить ваше изображение

DSS Images   Other Images


Публикации по объекту

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).

Five-colour photometry of OB-stars in the Southern Hemisphere
Observations of OB-stars, made in 1959 and 1960 at the Leiden SouthernStation near Hartebeespoortdam, South Africa, with the VBLUW photometerattached to the 90 cm light-collector, are given in this paper. They arecompared with photometry obtained by \cite[Graham (1968),]{gra68}\cite[Walraven & Walraven (1977),]{wal77} \cite[Lub & Pel(1977)]{lub77} and \cite[Van Genderen et al. (1984).]{gen84} Formulaefor the transformation of the present observations to those of\cite[Walraven & Walraven (1977)]{wal77} and \cite[Lub & Pel(1977)]{lub77} are given. Table 4 is only available in electronic format the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) orvia http://cdsweb.u-strasbg.fr/Abstract.html

Добавить новую статью


Внешние ссылки

  • - Внешних ссылок не найдено -
Добавить внешнюю ссылку


Группы:


Наблюдательные данные и астрометрия

Созвездие:Андромеда
Прямое восхождение:00h36m49.76s
Склонение:+25°10'09.7"
Видимая звёздная величина:8.456
Расстояние:274.725 парсек
Собственное движение RA:0.3
Собственное движение Dec:-17.3
B-T magnitude:9.969
V-T magnitude:8.581

Каталоги и обозначения:
Собственные имена
HD 1989HD 3378
TYCHO-2 2000TYC 1741-1931-1
USNO-A2.0USNO-A2 1125-00224194
HIPHIP 2908

→ Запросить дополнительные каталоги и обозначения от VizieR