시작하기     To Survive in the Universe    
Inhabited Sky
    News@Sky     천체사진     컬렉션     포럼     Blog New!     질문및답변     출판     로그인  

HD 197150


내용

사진

사진 업로드

DSS Images   Other Images


관련 글

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).

새 글 등록


관련 링크

  • - 링크가 없습니다. -
새 링크 등록


다음 그룹에 속해있음:


관측 및 측정 데이터

별자리:돌고래자리
적경:20h41m12.11s
적위:+18°12'13.7"
가시등급:8.703
거리:121.655 파섹
적경상의 고유운동:57.1
적위상의 고유운동:-2.4
B-T magnitude:9.299
V-T magnitude:8.753

천체목록:
일반명   (Edit)
HD 1989HD 197150
TYCHO-2 2000TYC 1638-509-1
USNO-A2.0USNO-A2 1050-18376150
HIPHIP 102076

→ VizieR에서 더 많은 목록을 가져옵니다.