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Spectroscopic binaries among Hipparcos M giants^,. I. Data, orbits, and intrinsic variations
Context: This paper is a follow-up on the vast effort to collect radialvelocity data for stars belonging to the Hipparcos survey. Aims: We aimat extending the orbital data available for binaries with M giantprimaries. The data presented in this paper will be used in thecompanion papers of this series to (i) derive the binary frequency amongM giants and compare it to that of K giants (Paper II); and (ii) analysethe eccentricity - period diagram and the mass-function distribution(Paper III). Methods: Keplerian solutions are fitted to radial-velocitydata. However, for several stars, no satisfactory solution could befound, even though the radial-velocity standard deviation is greaterthan the instrumental error, because M giants suffer from intrinsicradial-velocity variations due to pulsations. We show that theseintrinsic radial-velocity variations can be linked with both the averagespectral-line width and the photometric variability. Results: Wepresent an extensive collection of spectroscopic orbits for M giantswith 12 new orbits, plus 17 from the literature. On top of these, 1preliminary orbit yielded an approximate value for the eccentricity andthe orbital period. Moreover, to illustrate how the largeradial-velocity jitter present in Mira and semi-regular variables mayeasily be confused with orbital variations, we also present examples ofpseudo-orbital variations (in S UMa, X Cnc, and possibly in HD 115 521,a former IAU radial-velocity standard). Because of this difficulty, Mgiants involving Mira variables were excluded from our monitored sample.We finally show that the majority of M giants detected as X-ray sourcesare actually binaries. Conclusions: The data presented in this paperconsiderably increase the orbital data set for M giants, and will allowus to conduct a detailed analysis of the eccentricity - period diagramin a companion paper (Paper III).Based on observations carried out at the Swiss telescope installed atthe Observatoire de Haute Provence (OHP, France), and at the 1.93-m OHPtelescope. Full Tables 2, 3, and Table 6 are only available inelectronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr(130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/498/627
| Hipparcos red stars in the HpV_T2 and V I_C systems
For Hipparcos M, S, and C spectral type stars, we provide calibratedinstantaneous (epoch) Cousins V - I color indices using newly derivedHpV_T2 photometry. Three new sets of ground-based Cousins V I data havebeen obtained for more than 170 carbon and red M giants. These datasetsin combination with the published sources of V I photometry served toobtain the calibration curves linking Hipparcos/Tycho Hp-V_T2 with theCousins V - I index. In total, 321 carbon stars and 4464 M- and S-typestars have new V - I indices. The standard error of the mean V - I isabout 0.1 mag or better down to Hp~9 although it deteriorates rapidly atfainter magnitudes. These V - I indices can be used to verify thepublished Hipparcos V - I color indices. Thus, we have identified ahandful of new cases where, instead of the real target, a random fieldstar has been observed. A considerable fraction of the DMSA/C and DMSA/Vsolutions for red stars appear not to be warranted. Most likely suchspurious solutions may originate from usage of a heavily biased color inthe astrometric processing.Based on observations from the Hipparcos astrometric satellite operatedby the European Space Agency (ESA 1997).}\fnmsep\thanks{Table 7 is onlyavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/397/997
| Sixth Catalogue of Fundamental Stars (FK6). Part III. Additional fundamental stars with direct solutions
The FK6 is a suitable combination of the results of the HIPPARCOSastrometry satellite with ground-based data, measured over a longinterval of time and summarized mainly in the FK5. Part III of the FK6(abbreviated FK6(III)) contains additional fundamental stars with directsolutions. Such direct solutions are appropriate for single stars or forobjects which can be treated like single stars. Part III of the FK6contains in total 3272 stars. Their ground-based data stem from thebright extension of the FK5 (735 stars), from the catalogue of remainingSup stars (RSup, 732 stars), and from the faint extension of the FK5(1805 stars). From the 3272 stars in Part III, we have selected 1928objects as "astrometrically excellent stars", since their instantaneousproper motions and their mean (time-averaged) ones do not differsignificantly. Hence most of the astrometrically excellent stars arewell-behaving "single-star candidates" with good astrometric data. Thesestars are most suited for high-precision astrometry. On the other hand,354 of the stars in Part III are Δμ binaries in the sense ofWielen et al. (1999). Many of them are newly discovered probablebinaries with no other hitherto known indication of binarity. The FK6gives, besides the classical "single-star mode" solutions (SI mode),other solutions which take into account the fact that hidden astrometricbinaries among "apparently single-stars" introduce sizable "cosmicerrors" into the quasi-instantaneously measured HIPPARCOS proper motionsand positions. The FK6 gives, in addition to the SI mode, the "long-termprediction (LTP) mode" and the "short-term prediction (STP) mode". TheseLTP and STP modes are on average the most precise solutions forapparently single stars, depending on the epoch difference with respectto the HIPPARCOS epoch of about 1991. The typical mean error of anFK6(III) proper motion in the single-star mode is 0.59 mas/year. This isa factor of 1.34 better than the typical HIPPARCOS errors for thesestars of 0.79 mas/year. In the long-term prediction mode, in whichcosmic errors are taken into account, the FK6(III) proper motions have atypical mean error of 0.93 mas/year, which is by a factor of about 2better than the corresponding error for the HIPPARCOS values of 1.83mas/year (cosmic errors included).
| The 74th Special Name-list of Variable Stars
We present the Name-list introducing GCVS names for 3153 variable starsdiscovered by the Hipparcos mission.
| Fifth fundamental catalogue. Part 2: The FK5 extension - new fundamental stars
The mean positions and proper motions for 3117 new fundamental starsessentially in the magnitude range about 4.5 to 9.5 are given in thisFK5 extension. Mean apparent visual magnitude is 7.2 and is on average2.5 magnitudes fainter then the basic FK5 which has a mean magnitude of4.7. (The basic FK5 gives the mean positions and proper motions for theclassical 1535 fundamental stars). The following are discussed: theobservational material, reduction of observations, star selection, andthe system for the FK5 extension. An explanation and description of thecatalog are given. The catalog of 3117 fundamental stars for the equinoxand epoch J2000.0 and B1950.0 is presented. The parallaxes and radialvelocities for 22 extension stars with large forecasting effects aregiven. Catalogs used in the compilation of the FK5 fundamental catalogare listed.
| UBVRI Photometry of FKSZ Stars - Part One
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1987A&AS...70..369C&db_key=AST
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| Takýmyýldýz: | Irmak |
| Sað Açýklýk: | 03h54m58.62s |
| Yükselim: | -14°54'21.3" |
| Görünürdeki Parlaklýk: | 7.14 |
| Uzaklýk: | 310.559 parsek |
| özdevim Sað Açýklýk: | 3.6 |
| özdevim Yükselim: | -12.8 |
| B-T magnitude: | 9.377 |
| V-T magnitude: | 7.325 |
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