Tartalom
Képek
Kép feltöltése
DSS Images Other Images
Kapcsolódó cikkek
Observed Orbital Eccentricities
For 391 spectroscopic and visual binaries with known orbital elementsand having B0-F0 IV or V primaries, we collected the derivedeccentricities. As has been found by others, those binaries with periodsof a few days have been circularized. However, those with periods up toabout 1000 or more days show reduced eccentricities that asymptoticallyapproach a mean value of 0.5 for the longest periods. For those binarieswith periods greater than 1000 days their distribution of eccentricitiesis flat from 0 to nearly 1, indicating that in the formation of binariesthere is no preferential eccentricity. The binaries with intermediateperiods (10-100 days) lack highly eccentric orbits.
| Statistical Constraints for Astrometric Binaries with Nonlinear Motion
Useful constraints on the orbits and mass ratios of astrometric binariesin the Hipparcos catalog are derived from the measured proper motiondifferences of Hipparcos and Tycho-2 (Δμ), accelerations ofproper motions (μ˙), and second derivatives of proper motions(μ̈). It is shown how, in some cases, statistical bounds can beestimated for the masses of the secondary components. Two catalogs ofastrometric binaries are generated, one of binaries with significantproper motion differences and the other of binaries with significantaccelerations of their proper motions. Mathematical relations betweenthe astrometric observables Δμ, μ˙, and μ̈ andthe orbital elements are derived in the appendices. We find a remarkabledifference between the distribution of spectral types of stars withlarge accelerations but small proper motion differences and that ofstars with large proper motion differences but insignificantaccelerations. The spectral type distribution for the former sample ofbinaries is the same as the general distribution of all stars in theHipparcos catalog, whereas the latter sample is clearly dominated bysolar-type stars, with an obvious dearth of blue stars. We point outthat the latter set includes mostly binaries with long periods (longerthan about 6 yr).
| CHARM2: An updated Catalog of High Angular Resolution Measurements
We present an update of the Catalog of High Angular ResolutionMeasurements (CHARM, Richichi & Percheron \cite{CHARM}, A&A,386, 492), which includes results available until July 2004. CHARM2 is acompilation of direct measurements by high angular resolution methods,as well as indirect estimates of stellar diameters. Its main goal is toprovide a reference list of sources which can be used for calibrationand verification observations with long-baseline optical and near-IRinterferometers. Single and binary stars are included, as are complexobjects from circumstellar shells to extragalactic sources. The presentupdate provides an increase of almost a factor of two over the previousedition. Additionally, it includes several corrections and improvements,as well as a cross-check with the valuable public release observationsof the ESO Very Large Telescope Interferometer (VLTI). A total of 8231entries for 3238 unique sources are now present in CHARM2. Thisrepresents an increase of a factor of 3.4 and 2.0, respectively, overthe contents of the previous version of CHARM.The catalog is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/431/773
| Tidal Effects in Binaries of Various Periods
We found in the published literature the rotational velocities for 162B0-B9.5, 152 A0-A5, and 86 A6-F0 stars, all of luminosity classes V orIV, that are in spectroscopic or visual binaries with known orbitalelements. The data show that stars in binaries with periods of less thanabout 4 days have synchronized rotational and orbital motions. Stars inbinaries with periods of more than about 500 days have the samerotational velocities as single stars. However, the primaries inbinaries with periods of between 4 and 500 days have substantiallysmaller rotational velocities than single stars, implying that they havelost one-third to two-thirds of their angular momentum, presumablybecause of tidal interactions. The angular momentum losses increase withdecreasing binary separations or periods and increase with increasingage or decreasing mass.
| J - K DENIS photometry of a VLTI-selected sample of bright southern stars
We present a photometric survey of bright southern stars carried outusing the DENIS instrument equipped with attenuating filters. Theobservations were carried out not using the survey mode of DENIS, butwith individual target pointings. This project was stimulated by theneed to obtain near-infrared photometry of stars to be used in earlycommissioning observations of the ESO Very Large TelescopeInterferometer, and in particular to establish a network of brightcalibrator sources.We stress that near-infrared photometry is peculiarly lacking for manybright stars. These stars are saturated in 2MASS as well as in regularDENIS observations. The only other observations available for brightinfrared stars are those of the Two Micron Sky Survey dating from overthirty years ago. These were restricted to declinations above≈-30°, and thus cover only about half of the sky accessible fromthe VLTI site.We note that the final 2MASS data release includes photometry of brightstars, obtained by means of point-spread function fitting. However, thismethod only achieves about 30% accuracy, which is not sufficient formost applications.In this work, we present photometry for over 600 stars, each with atleast one and up to eight measurements, in the J and K filters. Typicalaccuracy is at the level of 0\fm05 and 0\fm04 in the J and K_s bands,respectively.Based on observations collected at the European Southern Observatory, LaSilla.Tables 1 and 2 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/413/1037
| Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i
This work is the second part of the set of measurements of v sin i forA-type stars, begun by Royer et al. (\cite{Ror_02a}). Spectra of 249 B8to F2-type stars brighter than V=7 have been collected at Observatoirede Haute-Provence (OHP). Fourier transforms of several line profiles inthe range 4200-4600 Å are used to derive v sin i from thefrequency of the first zero. Statistical analysis of the sampleindicates that measurement error mainly depends on v sin i and thisrelative error of the rotational velocity is found to be about 5% onaverage. The systematic shift with respect to standard values fromSlettebak et al. (\cite{Slk_75}), previously found in the first paper,is here confirmed. Comparisons with data from the literature agree withour findings: v sin i values from Slettebak et al. are underestimatedand the relation between both scales follows a linear law ensuremath vsin inew = 1.03 v sin iold+7.7. Finally, thesedata are combined with those from the previous paper (Royer et al.\cite{Ror_02a}), together with the catalogue of Abt & Morrell(\cite{AbtMol95}). The resulting sample includes some 2150 stars withhomogenized rotational velocities. Based on observations made atObservatoire de Haute Provence (CNRS), France. Tables \ref{results} and\ref{merging} are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/393/897
| CHARM: A Catalog of High Angular Resolution Measurements
The Catalog of High Angular Resolution Measurements (CHARM) includesmost of the measurements obtained by the techniques of lunaroccultations and long-baseline interferometry at visual and infraredwavelengths, which have appeared in the literature or have otherwisebeen made public until mid-2001. A total of 2432 measurements of 1625sources are included, along with extensive auxiliary information. Inparticular, visual and infrared photometry is included for almost allthe sources. This has been partly extracted from currently availablecatalogs, and partly obtained specifically for CHARM. The main aim is toprovide a compilation of sources which could be used as calibrators orfor science verification purposes by the new generation of largeground-based facilities such as the ESO Very Large Interferometer andthe Keck Interferometer. The Catalog is available in electronic form atthe 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/386/492, and from theauthors on CD-Rom.
| ICCD Speckle Observations of Binary Stars. XXIII. Measurements during 1982-1997 from Six Telescopes, with 14 New Orbits
We present 2017 observations of 1286 binary stars, observed by means ofspeckle interferometry using six telescopes over a 15 year period from1982 April to 1997 June. These measurements constitute the 23dinstallment in CHARA's speckle program at 2 to 4 m class telescopes andinclude the second major collection of measurements from the MountWilson 100 inch (2.5 m) Hooker Telescope. Orbital elements are alsopresented for 14 systems, seven of which have had no previouslypublished orbital analyses.
| Correlation of the HIPPARCOS and Allegheny Observatory Parallax Catalogs
No significant difference is found between the systems of the Hipparcosand Allegheny Observatory MAP parallax catalogs. The correlation of theparallaxes of 63 stars common to both programs is 0.9995 +/- 0.0001,with an average standard deviation of the difference of 0.0023". Whilethere is no indication of systematic difference in the two programs, ourstudy suggests that the formal errors in one or both catalogs aresomewhat underestimated.
| Mass determination of astrometric binaries with Hipparcos. III. New results for 28 systems
This paper is the third of a series devoted to the determination ofstellar masses from Hipparcos data. This is a continuation of Martin etal. (1997), who introduced the theory and assessed the performance ofthe method from simulated data, and of a second paper with the firstresults for 46 systems, ( te[Martin & Mignard 1998]{Mar98}). Theorbit file maintained by the CHARA group and new publications of orbitalelements made the processing of 70 additional candidate systemspossible, including 28 of the 145 systems already tested in the previouswork. Significant results were obtained on 22 systems, with relativeaccuracy better than 25% for the masses of 17 binaries. New estimatesare also given for 6 systems previously investigated, thanks to reliablevalues of the magnitude difference from the Hipparcos catalogue ( te[ESA1997]{ESA97}). New orbital elements are proposed for HIP 12623 (12Persei) from speckle/spectroscopic measurements. Results are discussedfor each system, alongside the mass-luminosity relation based onHipparcos magnitudes and distances.
| ICCD Speckle Observations of Binary Stars. XVII. Measurements During 1993-1995 From the Mount Wilson 2.5-M Telescope.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.1639H&db_key=AST
| ICCD Speckle Observations of Binary Stars. XVI. Measurements During 1982-1989 from the Perkins 1.8-M Telescope.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.1623F&db_key=AST
| Binary Star Orbits from Speckle Interferometry. XI. Orbits of Twelve Lunar Occultation Systems.
Stars detected as double by lunar occultation are logical targets forspeckle interferometric and spectroscopic investigations. This paperpresents twelve orbits for interferometric systems; eight of these hadno previous orbits and the other four have new orbit determinationswhich represent improvements on previously published elements. Wheretrigonometric parallaxes are not available, spectroscopic parallaxes arecalculated, and model-dependent masses are determined for ten componentswhose results seem most reasonable.
| ICCD Speckle Observations of Binary Stars.XV.An Investigation of Lunar Occultation Systems
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....112.2260M&db_key=AST
| Speckles and Shadow Bands
Speckle interferometry has for the past two decades provided a means tomeasure very accurate relative positions of binary stars, data crucialto the fundamental determination of basic stellar parameters. As atechnique for observing small angular separations speckle interferometryis exceeded only by long baseline interferometry (a technique still ininfancy) and the observation of lunar occultation phenomena. As the moonpasses in front of stars the light coming from those stars is occulted.Occultations of binary stars can determine relative intensities and canmeasure separations which are comparable to those measured bylong-baseline interferometers. The data are difficult to interpret sincethe measured separation is a projection of the true angular separationand non-standard filters are often used. No complete listing of alloccultation measures has been published since the compilation of DavidEvans (IAU Colloquium No. 62, Current Techniques in Double and MultipleStar Research, Lowell Observatory Bulletin No. 167, 1981, eds.Harrington, R.A. \& Franz, O.G., Lowell Observatory, Flagstaff). Thedissertation presents 772 measures of 357 systems, an increase of 60\%over the Evans catalog. The methodology of speckle interferometry ispresented, followed by 362 re-reduction measures and 253 new measures.The re-reduction measures were cases where prior analysis showed nocompanion. With improved reduction algorithms, detection frequencysignificantly increased. One observation in eight previously showing nocompanion produced a measurable result. Results were obtained with the1.8-m Perkins telescope of Lowell Observatory, the 2.5-m Hookertelescope of Mt. Wilson Observatory, the 3.8-m Mayall telescope of KittPeak National Observatory and the 4.0-m telescope at Cerro TololoInterAmerican Observatory. All but 130 of the occultation objects havespeckle observations. The likelihood of future detection by speckle isconsidered. An analysis of 131 negative results is presented. Of theremaining 96 systems, 66 have been detected by speckle interferometry,13 for the first time, and 17 new orbits have been calculated. Of theseorbits, five (HR 793 = Bla Aa, ADS 3608 = A 1844, HR 3880 = McA 34, HR5652 = B 2531 Aa, HR 7776 = $\beta$ Cap) have improved elements overprevious orbit calculations, four (BD$+$24~1805 = Cou 929, ADS 17052 = A2700, HR 9041 = Fin 359, ADS 17111 = A 2100) have previous butsignificantly different orbits, five (HR 132 = McA 1 Aa, HR 1808 = McA19 Aa, HR 2343 = Btz Aa, HR 8060 = Fin 328, HR 8704 = McA 73) are firstorbits, and three (HR 763 = McA 7, HR 2130 = McA 24, HR 2846 = McA 30Aa) are first orbits of spectroscopic binaries. The occultation catalog,speckle measures, and new orbits will be presented in subsequent CHARApublications. The detection of occultation binaries by speckleinterferometry seems to be predictable, however, there appear to be asmall sample of occultation binaries which cannot be detected. These maybe spurious. Lunar occultation measures place a good limit on $\Delta$mfor speckle of about 3.0. CHARA hopes to complete a survey of alloccultation objects with current scheduled runs which should result in afurther five to ten objects resolved for the first time. While the rateof occultation measures has dropped significantly, they are stillcontinuing to provide useful complementary data for other binary starmethods. (SECTION: Dissertation Summaries)
| The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995ApJS...99..135A&db_key=AST
| Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
| Observations of lunar occultations at Observatoire de la Cote d'Azur.
The results of 114 photoelectric observations are analysed. They wereobtained at the two stations of O.C.A.: Calern and Nice Observatories.We first give a short description of the two photometers used and thenwe present the interactive reduction method. The astrometric andphotometric parameters are derived from each light-curve. Finally wesummarize the results and discuss about the non point-like occultedstars: we present 38 double star measurements, for 16 objects, and 11determinations of angular diameters, for 4 objects.
| All-sky Stromgren photometry of speckle binary stars
All-sky Stromgren photometric observations were obtained for 303 specklebinaries. Most stars were in the range of V = 5-8. These data, whencombined with ratios of intensities from the CHARA speckle photometryprogram, will allow the determination of photometric indices for theindividual components of binary stars with separations as small as 0.05arcsec. These photometric indices will complement the stellar massesfrom the speckle interferometry observations to provide a much improvedmass-luminosity relationship.
| ICCD speckle observations of binary stars. X - A further survey for duplicity among the bright stars
Speckle interferometric observations are reported for 1123 starsselected from the Yale Bright Star Catalogue (BSC) in a continuingeffort to detect new binaries among the bright stars. Thirty-twopreviously unresolved binaries have been detected, including companionsto Xi UMa and 15 S Mon. Measures of 107 previously resolved systems,many of which resulted from earlier speckle observations, are alsopresented. No evidence of duplicity within a specific (m, Delta-m, rho)window of detectability was found for 984 bright stars. Many of thesystems discovered earlier have shown significant orbital motions, andwe present preliminary orbital elements for six binaries. This efforthas resulted in the discovery of 75 new, bright binaries. We considersome aspects of the duplicity frequencies among the diverse spectral andluminosity classes represented in this sample. We anticipate that thecompletion of a speckle survey of the BSC would lead to the discovery ofat least 200 additional binary systems with angular separations mostlybelow 0.20 arcsec. Many of these will have periods of the order of onedecade and will be accessible to complementary radial velocity programsof enhanced precision.
| An astrometric study of the Mira variable R Leonis and the occultation binary 19 Leonis
The Multichannel Astrometric Photometer (MAP) was used to determineparallaxes of stars in the region centered on the Mira variable RLeonis. R Leonis, with a parallax of 8.3 +/- 1.0 mas (120 +/- 15 pc), issignificantly closer than most recent estimates. At visual wavelengths,its mean physical diameter is 612 +/- 96 times that of the sun. Thephotocentric motion of R Leonis is not suggestive of either optical ororbital companions, excluding possible secondary components over a widerange of magnitudes as well as orbital periods of up to approximatelyone decade. Nineteen Leonis, an occultation-speckle binary with awell-determined orbit and a reference star in the R Leonis field, has adistance of 92.6 +/- 12 pc. The 15.2 yr period binary exhibits a slightperturbation during the 4 yr of MAP observations. The similar primaryand secondary of this A7 Vn system are 2.41 +/- 0.96 and 2.31 +/- 0.92solar masses, respectively.
| Absolute quadrant determinations from speckle observations of binary stars
Vector-autocorrelation techniques are highly suited to extractingastrometric information from very large volumes of speckle data in nearreal time, but they inherently introduce a 180-deg ambiguity in theposition-angle measurement. This can be a problem in determining theorbital motions in binaries, so an algorithm is presented whichmaintains most of the simplicity of vector autocorrelation whileremoving the quadrant ambiguity. Results are provided fromabsolute-quadrant determinations for 66 binary star systems firstresolved by the long-term GSU/CHARA speckle program. The algorithm isused to eliminate the period ambiguity in the orbit of the close visualbinary ADS 9744.
| Interferometric observations of double stars in 1986-1990
A tabulation is presented for the measurements of double stars that havebeen conducted with the photometric phase-grating interferometer of theMt. Sanglok 1-m reflector. The tabulation encompasses the observationepoch, the position angle, the separation in arcsec, the magnitudedifference, formal errors in P.A. and separation, SAO number, andcoordinates for 2000.0.
| A first catalogue of speckle-interferometric measurements of binary stars made with 6-m telescope of the USSR AS.
Not Available
| Spectroscopic parallaxes of MAP region stars from UBVRI, DDO, and uvbyH-beta photometry
This paper presents the results of spectral type and luminosityclassification of reference stars in the Allegheny Observatory MAPparallax program, using broadband and intermediate-band photometry. Inaddition to the use of UBVRI and DDO photometric systems, the uvbyH-betaphotometric system was included for classification of blue (B - V lessthan 0.6) reference stars. The stellar classifications made from thephotometry are used to determine spectroscopic parallaxes. Thespectroscopic parallaxes are used in turn to adjust the relativeparallaxes measured with the MAP to absolute parallaxes. A new methodfor dereddening stars using more than one photometric system ispresented. In the process of dereddening, visual extinctions, spectraltypes, and luminosity classes are determined, as well as a measure ofthe goodness of fit. The measure of goodness of fit quantifiesconfidence in the stellar classifications. It is found that the spectraltypes are reliable to within 2.5 spectral subclasses.
| ICCD speckle observations of binary stars. V - Measurements during 1988-1989 from the Kitt Peak and the Cerro Tololo 4 M telescopes
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1990AJ.....99..965M&db_key=AST
| Photometry of the asteroids 2, 4, 16, 17, 19, 20, 22, and 505
Results of photometric observations of several asteroids observed during1980-1984 are presented. Light curves, epochs of extrema, magnitudes,and colors are presented.
| ICCD speckle observations of binary stars. IV - Measurements during 1986-1988 from the Kitt Peak 4 M telescope
One thousand five hundred and fifty measurements of 1006 binary starsystems observed mostly during 1986 through mid-1988 by means of speckleinterferometry with the KPNO 4-m telescope are presented. Twenty-onesystems are directly resolved for the first time, including newcomponents to the cool supergiant Alpha Her A and the Pleiades shellstar Pleione. A continuing survey of The Bright Star Catalogue yieldedeight new binaries from 293 bright stars observed. Corrections tospeckle measures from the GSU/CHARA ICCD speckle camera previouslypublished are presented and discussed.
| Orbital Elements of Eight Interferometric Binary Stars
Not Available
| Interferometric Observations of Double Stars in 1985 and 1986
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1988A&AS...72..563T&db_key=AST
|
Új cikk hozzáadása
Kapcsolódó hivatkozások
- - (nincs kapcsolódó hivatkozás) -
Új link hozzáadása
Besorolás csoportokba:
|
Pozíciós és asztrometriai adatok
| Csillagkép: | Oroszlán |
| Rektaszcenzió: | 09h47m25.90s |
| Deklináció: | +11°34'06.0" |
| Vizuális fényesség: | 6.45 |
| Távolság: | 89.767 parszek |
| RA sajátmozgás: | -48.5 |
| Dec sajátmozgás: | -1.4 |
| B-T magnitude: | 6.752 |
| V-T magnitude: | 6.477 |
Katalógusok és elnevezések:
|
