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HD 4731

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관련 글

The long-period companions of multiple stars tend to have moderate eccentricities We examined the statistics of an angle gamma between the radius vectorof a visual companion of a multiple star and the vector of its apparentrelative motion in the system. Its distribution f(gamma ) is related tothe orbital eccentricity distribution in the investigated sample. Wefound that for the wide physical subsystems of the 174 objects from theMultiple Star Catalogue f(gamma ) is bell-shaped. The Monte-Carlosimulations have shown that our f(gamma ) corresponds to the populationof the moderate-eccentricity orbits and is not compatible with thelinear distribution f(e)=2e which follows from stellar dynamics andseems to hold for wide binaries. This points to the absence of highlyelongated orbits among the outer subsystems of multiple stars. Theconstraint of dynamical stability of triple systems is not sufficient toexplain the ``rounded-off'' outer orbits; instead, we speculate that itcan result from the angular momentum exchange in multiple systems duringtheir early evolution.
The South Galactic Pole - Results from uvby-beta photometry of 572 O-F stars Photometric observations on the uvby-beta system are presented for 572O-F stars within about 20 deg of the South Galactic Pole. Theinterstellar extinction near the pole is found to be zero out to 400 pcfrom the sun, in agreement with the H I maps of Burstein and Heiles(1982). Several evolved and Population II objects are identified.
Mesures d'etoiles doubles faites a Nice. Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&AS...33..275M&db_key=AST
Stellar population samples at the galactic poles. III - UBVRI observations of proper motion stars near the south pole and the luminosity laws for the halo and old disk populations Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976ApJS...30..351E&db_key=AST
Photographic measures of double stars Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970A&AS....1..357T&db_key=AST

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관측 및 측정 데이터

별자리:	고래자리
적경:	00^h49^m18.33^s
적위:	-21Â°23'50.5"
가시등급:	8.848
거리:	317.46 파섹
적경상의 고유운동:	37.6
적위상의 고유운동:	8.5
B-T magnitude:	9.364
V-T magnitude:	8.891

천체목록:

일반명	(Edit)
HD 1989	HD 4731
TYCHO-2 2000	TYC 5850-2582-1
USNO-A2.0	USNO-A2 0675-00317516
HIP	HIP 3845

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