내용
사진
사진 업로드
DSS Images Other Images
관련 글
Evolved GK stars near the sun. I - The old disk population
A sample of nearly two thousand GK giants with intermediate band, (R,I),DDO and Geneva photometry has been assembled. Astrometric data is alsoavailable for most of the stars. The some 800 members of the old diskpopulation in the sample yield accurate luminosities (from two sources),reddening values and chemical abundances from calibrations of thephotometric parameters. Less than one percent of the objects arepeculiar in the sense that the flux distribution is abnormal. Thepeculiarity is signaled by strong CH (and Ba II) and weak CH. The CH+stars are all spectroscopic binaries, probably with white dwarfcompanions, whereas the CH- stars are not. A broad absorption band,centered near 3500 A, is found in the CH+ stars whereas the CH- objectshave a broad emission feature in the same region. The intensity of theseabsorptions and emissions are independent of the intensity of abnormalspectral features. Ten percent of the old disk sample have a heavyelement abundance from one and a half to three times the solar value.The distribution of the heavy element abundances is nearly a normal onewith a peak near solar abundance and ranges three times to one sixthsolar. The distribution of the (U, V) velocities is independent of theheavy element abundance and does not appear to be random. Ten percent ofthe old disk stars show a CN anomaly, equally divided between CN strongand CN weak. Several stars of individual astrometric or astrophysicalimportance are isolated.
| Radial velocities of southern stars obtained with the photoelectric scanner CORAVEL. III - 790 late-type bright stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1985A&AS...59...15A&db_key=AST
| Close visual binaries. I - MK classifications
Each component of 170 close visual binaries has been classified with newprocedures for controlling contamination problems. These classificationsare presented and are shown to be on the MK system. Two sources of areascanner UBV photometry were compared in order to establish homogeneousphotometric as well as spectroscopic data. From a consideration ofsystematic errors in the V magnitude difference (Delta V) betweencomponents the photometry of Hurly and Warner (1983) is to be preferred.Absolute magnitudes for each binary are derived from Delta V via atested MK - M(v) map.
| Close visual binaries. II - Quantitative test of isochrones
Homogeneous and accurate color-magnitude data are available from Paper Ifor each component of 56 close visual binaries, 30 with evolvedcomponents. The 21 binaries with main-sequence primaries are comparedwith new Yale isochrones to determine the appropriate isochronecomposition: Y = 0.25, Z = 0.04. Explanations are given for eightbinaries found to be inconsistent with this isochrone. Some of theremaining binaries suggest a decrease by 0.5 in the mixing lengthparameter for the reddest main-sequence stars, and either a smallerdecrease or mass loss in the subgiant and giant phase of evolution. Ingeneral, the mean apparent age difference between binary components (0.0+ or - 0.1 Gyr) shows stellar evolution to be well modeled by the newYale isochrones.
| Close visual binaries. III - Parameters and evolutionary status
New Yale isochrones, which have been tested for accuracy by Corbally(1984), provide the means to investigate interesting visual binaries,especially those whose classifications and photometry do not match well.Various parameters are deduced for those binaries which fitted theisochrones (e.g. ages, metal abundances, luminosities of peculiarstars); various solutions are systematically developed for those whichdid not fit; and a likely status of evolution is proposed (e.g.,duplicity of the components, premain-sequence, blue straggler,horizontal branch, optical pair, data inaccuracies). Evolution aroundthe helium flash and diffusion theory are briefly considered. Theseparameters and statuses provide a wealth of new stellar data andsuggestions for further investigation.
| Area Scanner Observations of Close Visual Double Stars - Part Two - Results for 153 Southern Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1983MNRAS.202..761H&db_key=AST
| Erratum - Discordances Between SAO and HD Numbers for Bright Stars
Not Available
| Combined-light UBV Photometry of 103 Bright Southern Visual Doubles
Not Available
| Narrow-Band and Broad-Band Photometry of Red Stars. III. Southern Giants
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970ApJ...161..199E&db_key=AST
|
새 글 등록
관련 링크
새 링크 등록
다음 그룹에 속해있음:
|
관측 및 측정 데이터
천체목록:
|
INHABITED SKY
