내용
사진
사진 업로드
DSS Images Other Images
관련 글
VSOP: the variable star one-shot project. I. Project presentation and first data release
Context: About 500 new variable stars enter the General Catalogue ofVariable Stars (GCVS) every year. Most of them however lackspectroscopic observations, which remains critical for a correctassignement of the variability type and for the understanding of theobject. Aims: The Variable Star One-shot Project (VSOP) is aimed at (1)providing the variability type and spectral type of all unstudiedvariable stars, (2) process, publish, and make the data available asautomatically as possible, and (3) generate serendipitous discoveries.This first paper describes the project itself, the acquisition of thedata, the dataflow, the spectroscopic analysis and the on-lineavailability of the fully calibrated and reduced data. We also presentthe results on the 221 stars observed during the first semester of theproject. Methods: We used the high-resolution echelle spectrographsHARPS and FEROS in the ESO La Silla Observatory (Chile) to survey knownvariable stars. Once reduced by the dedicated pipelines, the radialvelocities are determined from cross correlation with synthetic templatespectra, and the spectral types are determined by an automatic minimumdistance matching to synthetic spectra, with traditional manual spectraltyping cross-checks. The variability types are determined by manuallyevaluating the available light curves and the spectroscopy. In thefuture, a new automatic classifier, currently being developed by membersof the VSOP team, based on these spectroscopic data and on thephotometric classifier developed for the COROT and Gaia space missions,will be used. Results: We confirm or revise spectral types of 221variable stars from the GCVS. We identify 26 previously unknown multiplesystems, among them several visual binaries with spectroscopic binaryindividual components. We present new individual results for themultiple systems V349 Vel and BCGru, for the composite spectrum star V4385Sgr, for the T Tauri star V1045 Sco, andfor DM Boo which we re-classify as a BY Draconisvariable. The complete data release can be accessed via the VSOP website.Based on data obtained at the La Silla Observatory, European SouthernObservatory, under program ID 077.D-0085.
| Kinematics of Hipparcos Visual Binaries. II. Stars with Ground-Based Orbital Solutions
This paper continues kinematical investigations of the Hipparcos visualbinaries with known orbits. A sample, consisting of 804 binary systemswith orbital elements determined from ground-based observations, isselected. The mean relative error of their parallaxes is about 12% andthe mean relative error of proper motions is about 4%. However, even 41%of the sample stars lack radial velocity measurements. The computedGalactic velocity components and other kinematical parameters are usedto divide the stars with known radial velocities into kinematical agegroups. The majority (92%) of binaries from the sample are thin diskstars, 7.6% have thick disk kinematics and only two binaries have halokinematics. Among them, the long-period variable Mira Ceti has a verydiscordant {Hipparcos} and ground-based parallax values. From the wholesample, 60 stars are ascribed to the thick disk and halo population.There is an urgent need to increase the number of the identified halobinaries with known orbits and substantially improve the situation withradial velocity data for stars with known orbits.
| The 74th Special Name-list of Variable Stars
We present the Name-list introducing GCVS names for 3153 variable starsdiscovered by the Hipparcos mission.
| Micrometer measurements of southern double stars made at The Observatory of Llano del Hato at Merida (Venezuela)
We present 93 micrometer measurements of 46 double stars observed withthe 65 cm refractor at the Llano del Hato Observatory (Merida,Venezuela).
| Measures of southern visual double stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977PASP...89..588H&db_key=AST
|
새 글 등록
관련 링크
새 링크 등록
다음 그룹에 속해있음:
|
관측 및 측정 데이터
천체목록:
|
