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

TYC 1957-257-1


내용

사진

사진 업로드

DSS Images   Other Images


관련 글

Lithium Abundances in Wide Binaries with Solar-Type Twin Components
We present high-resolution spectroscopic observations of the Li Iresonance line in a sample of 62 stars that belong to 31 common propermotion pairs with twin F- or G-type components. Photospheric abundancesof lithium were derived by spectral synthesis analysis. For seven of thepairs, we have measured large lithium abundance differences. Elevenother pairs have components with similar lithium abundances. We cannotdetermine if the remaining 13 pairs have lithium differences because wedid not detect the Li I lines, and hence we can only provide upperlimits to the abundances of both stars. Our results demonstrate thattwin stars do not always share the same lithium abundances. Lithiumdepletion in solar-type stars does not only depend on age, mass, andmetallicity. This result is consistent with the spread in lithiumabundances among solar-type stars in the solar-age open cluster M67. Ourstars are brighter than the M67 members of similar spectral type, makingthem good targets for detailed follow-up studies that could shed lighton the elusive mechanism responsible for the depletion of lithium duringthe main-sequence evolution of the Sun and solar-type stars.

Common proper motion stars in the AGK 3
A search was made of common-proper-motion (CPM) systems among AGK 3stars. The selection of physical systems was based upon the ratiobetween the angular separation (rho) and the proper motion (mu); the CPMstars found are presented in two tables. Table I lists systems withrho/mu less than 1000 years. It contains 326 entries, and the proportionof optical pairs is estimated to be 1 percent. Table II lists systemswith rho/mu in the range 1000 to 3500 years; it contains 113 systems,but only 60 percent of them are physical. Nevertheless, these systemsoften have separations larger than 10,000 AU and are the mostinteresting for the study of the tail of the distribution function ofthe semimajor axes.

Discovery of microvariability in normal stars - Analysis of six main sequence stars
Six stars of spectral type A2 V-KI V have been observed to study themicrovariability of the normal main sequence stars. A method of photoncounting is used with a 48 cm telescope. Microvariability with anamplitude of 0.001-0.003 mag appears to be specific for the majority ofnormal stars while possessing a poliharmonic character, and it issuggested that the microvariability for the normal main sequence starscan be connected with nonradial pulsations.

새 글 등록


관련 링크

  • - 링크가 없습니다. -
새 링크 등록


다음 그룹에 속해있음:


관측 및 측정 데이터

별자리:게자리
적경:09h08m27.16s
적위:+27°32'35.3"
가시등급:8.236
거리:43.917 파섹
적경상의 고유운동:-49.9
적위상의 고유운동:75.5
B-T magnitude:8.941
V-T magnitude:8.295

천체목록:
일반명   (Edit)
TYCHO-2 2000TYC 1957-257-1
USNO-A2.0USNO-A2 1125-05828066
HIPHIP 44864

→ VizieR에서 더 많은 목록을 가져옵니다.