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Two-colour photometry for 9473 components of close Hipparcos double and multiple stars
Using observations obtained with the Tycho instrument of the ESAHipparcos satellite, a two-colour photometry is produced for componentsof more than 7 000 Hipparcos double and multiple stars with angularseparations 0.1 to 2.5 arcsec. We publish 9473 components of 5173systems with separations above 0.3 arcsec. The majority of them did nothave Tycho photometry in the Hipparcos catalogue. The magnitudes arederived in the Tycho B_T and V_T passbands, similar to the Johnsonpassbands. Photometrically resolved components of the binaries withstatistically significant trigonometric parallaxes can be put on an HRdiagram, the majority of them for the first time. Based on observationsmade with the ESA Hipparcos satellite.
| Speckle Interferometry of New and Problem HIPPARCOS Binaries
The ESA Hipparcos satellite made measurements of over 12,000 doublestars and discovered 3406 new systems. In addition to these, 4706entries in the Hipparcos Catalogue correspond to double star solutionsthat did not provide the classical parameters of separation and positionangle (rho,theta) but were the so-called problem stars, flagged ``G,''``O,'' ``V,'' or ``X'' (field H59 of the main catalog). An additionalsubset of 6981 entries were treated as single objects but classified byHipparcos as ``suspected nonsingle'' (flag ``S'' in field H61), thusyielding a total of 11,687 ``problem stars.'' Of the many ground-basedtechniques for the study of double stars, probably the one with thegreatest potential for exploration of these new and problem Hipparcosbinaries is speckle interferometry. Results are presented from aninspection of 848 new and problem Hipparcos binaries, using botharchival and new speckle observations obtained with the USNO and CHARAspeckle cameras.
| The Tokyo PMC catalog 90-93: Catalog of positions of 6649 stars observed in 1990 through 1993 with Tokyo photoelectric meridian circle
The sixth annual catalog of the Tokyo Photoelectric Meridian Circle(PMC) is presented for 6649 stars which were observed at least two timesin January 1990 through March 1993. The mean positions of the starsobserved are given in the catalog at the corresponding mean epochs ofobservations of individual stars. The coordinates of the catalog arebased on the FK5 system, and referred to the equinox and equator ofJ2000.0. The mean local deviations of the observed positions from theFK5 catalog positions are constructed for the basic FK5 stars to comparewith those of the Tokyo PMC Catalog 89 and preliminary Hipparcos resultsof H30.
| UBVJHKLM Photometry of Nova Cygni 1992
Not Available
| UBVRI Magnitudes for Four Margoni and Stagni Variables and Comparison Stars for Them
Not Available
| Analysis of Neckel and Chini standard stars in the UBVRI photometric system
This paper studies the list of 60 faint standard stars of Neckel andChini (1980) in the UBVRI Johnson photometric system. We have re-reducedthe standard stars using our own method of reduction from a large numberof selected observations made at the Observatorio Astronomico Nacionaland at the Centro Astronomico Hispano-Aleman, both at Calar Alto, Spain,and at the Observatorio del Roque de los Muchachos, La Palma Island,Spain. The reduction method used is explained and the results are givenfor the four colors used: (B-V), (U-B), (V-R), and (V-I), together withthe V magnitude, that is, we have corrected many standard stars for eachcolor and magnitude. These results are supported with graphs whereresidual color is plotted against corresponding color (or magnitude).Finally, our (V-R) and (V-I) results are compared to those of Taylor etal. (1989), with a good correspondence.
| The symbiotic eclipsing variable star CI CYG - Results of UBV and UBVRI photometric observations during 1973-1988
Photometric observations of CI Cyg carried out at the CrimeanAstrophysical Observatory during 1973-1988 are reported. It is shownthat after the active state which began in 1971, the variable becamequiescent by the mid-1980s. A comparison of CI Cyg's photometricbehavior in the active and quiescent states is presented.
| Radial-velocity measurements. III - Ground observations accompanying the HIPPARCOS satellite observation program: Measurements of the radial velocities of 391 stars in 12 fields
The radial velocities of 391 stars, obtained with the Fehrenbachobjective prism associated to the Schmidt telescope of the Observatoirede Haute-Provence are presented. These stars belong to fields speciallychosen for containing several Hipparcos input catalog star members. Eachfield is presented independently. The list includes HD and BDidentifiers when available, 1950 coordinates, spectral type, and B and Vmagnitudes as they appear in the CSI catalog, the radial velocity, theprobable error, the number of independent measurements and commentariessuch as known radial velocity and their origin.
| The properties of the Neckel-Chini VRI system
Cousins (1980) data for 54 of the standard stars of Neckel and Chini(1980) and published measurements are used to investigate the propertiesof the Neckel-Chini VRI system. For red stars, this system diverges fromthe Johnson (1962) system, despite frequent claims of identity betweenthe two. The Neckel-Chini and Cousins systems, however, are closelycomparable. Both of these conclusions were previously reached in a paperby Bessell (1983); fair to good quantitative agreement with his resultsare obtained. Reddening ratios, the scatter in the Neckel-Chinistandard-star data, and the effect of this scatter on publishedmeasurements for program stars, are discussed. Transformations from theNeckel-Chini system to the Cousins system are given.
| The Baade-Wesselink method applied to field RR Lyrae stars. I - UBVRI photoelectric and radial velocity data
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1987A&AS...69..135C&db_key=AST
| Sixty faint UBVRI standards
A list of 60 faint UBVRI standards is presented. Their UBV magnitudesare in the system introduced by Johnson (1955) and their V-R and V-Icolors are in the system of the Arizona Tonantzintla catalogue byIriarte et al. (1965). These stars are spread over an equatorial belt atan angle less than 30 deg, so that they can be observed as well fromnorthern as from southern sites.
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Группы:
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Наблюдательные данные и астрометрия
| Созвездие: | Лисичка |
| Прямое восхождение: | 20h33m18.24s |
| Склонение: | +27°27'26.6" |
| Видимая звёздная величина: | 8.985 |
| Расстояние: | 416.667 парсек |
| Собственное движение RA: | 6.4 |
| Собственное движение Dec: | 3.7 |
| B-T magnitude: | 9.08 |
| V-T magnitude: | 8.993 |
Каталоги и обозначения:
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