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

HD 22847


내용

사진

사진 업로드

DSS Images   Other Images


관련 글

High-resolution Doppler images of the spotted contact binary AE Phe
We present Doppler images of the short period (P= 0.362 d) W UMa binaryAE Phe. In order to obtain the necessary S/N ratio and time resolutionrequired to see individual star-spot features in highly rotationallybroadened profiles, we use least-squares deconvolution, which makes useof the information content of the several thousand lines in a typicalechelle spectrum. This yields a single rotation profile (free ofsidelobes due to blending) per spectrum with a typical S/N ratio ofseveral thousand.We use radial velocity curves, generated from standard profile fittingtechniques, to measure velocity amplitudes and the mass ratio. Failureto model star-spots with this method leads to a biased set of values,and we show that an imaging code is essential if accurate systemparameters are to be derived.Images are reconstructed from four nights of data which revealstar-spots at most latitudes on both components of the common envelopesystem. Our model requires that the primary component be several hundredK cooler than the secondary in order to reproduce the profile depthchanges with phase. In a two-temperature imaging model, we interpretthis as being due to 27 per cent greater - but unresolved - spot fillingon the primary relative to the secondary component. The images revealthat dark spots are present on both stars at various latitudes andlongitudes. Star-spots are also found in the neck region of bothcomponents, which appear to be darker on the side of each star leadingin rotation phase - particularly on the secondary component. Weinvestigate the reproducibility of the images from night to night andconclude that the star-spots evolve significantly on very shorttime-scales, of the order of 1 d. This is significantly faster than theweek time-scales found on active single stars and the Sun.

새 글 등록


관련 링크

  • - 링크가 없습니다. -
새 링크 등록


다음 그룹에 속해있음:


관측 및 측정 데이터

별자리:페르세우스자리
적경:03h41m38.23s
적위:+39°41'58.9"
가시등급:8.94
거리:621.118 파섹
적경상의 고유운동:5.3
적위상의 고유운동:0.3
B-T magnitude:9.022
V-T magnitude:8.947

천체목록:
일반명   (Edit)
HD 1989HD 22847
TYCHO-2 2000TYC 2867-503-1
USNO-A2.0USNO-A2 1275-02569325
HIPHIP 17251

→ VizieR에서 더 많은 목록을 가져옵니다.