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HD 31747


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Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics
The Catalogue, available at the Centre de Données Stellaires deStrasbourg, consists of 13 573 records concerning the results obtainedfrom different methods for 7778 stars, reported in the literature. Thefollowing data are listed for each star: identifications, apparentmagnitude, spectral type, apparent diameter in arcsec, absolute radiusin solar units, method of determination, reference, remarks. Commentsand statistics obtained from CADARS are given. The Catalogue isavailable 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/qcar?J/A+A/367/521

Maximum separations among cataloged binaries
The paper classifies many of the widest common-motion binaries listed inthe Aitken catalog and list 72 physical pairs with known photoelectricphotometry, 31 physical pairs without good photometry, and 27 opticalpairs. As a function of primary types, the physical systems have upperlimits to their separations that are exceeded by some of the opticalpairs. The fact that optical pairs occur with larger separations impliesthat the limits are real ones and not just catalog limitations. Thoselimits (in AU) are expressed by 2500 M1 exp 1.54 for B5-KO main-sequenceprimaries. The same limits hold for the Trapezium and hierarchicalsystems studied previously.

The local system of early type stars - Spatial extent and kinematics
Published uvby and H-beta photometric data and proper motions arecompiled and analyzed to characterize the structure and kinematics ofthe bright early-type O-A0 stars in the solar vicinity, with a focus onthe Gould belt. The selection and calibration techniques are explained,and the data are presented in extensive tables and graphs and discussedin detail. The Gould belt stars of age less than 20 Myr are shown togive belt inclination 19 deg to the Galactic plane and node-lineorientation in the direction of Galactic rotation, while the symmetricaldistribution about the Galactic plane and kinematic properties (purecircular differential rotation) of the belt stars over 60 Myr oldresemble those of fainter nonbelt stars of all ages. The unresolveddiscrepancy between the expansion observed in the youngest nearby starsand the predictions of simple models of expansion from a point isattributed to the inhomogeneous distribution of interstellar matter.

Confirmation among visual multiples of an increase of AP stars with age
Open clusters with ages below certain threshold values contain no Apstars and those with greater ages contain numbers of Ap stars thatapparently increase with age. But in view of the few young clustersstudied, the data could also be interpreted in terms of randomdifferences in the frequencies of Ap stars between individual clusters,rather than an age effect. Data on 77 field visual multiple systems(that originated from many different clusters and associations) in whichthe primaries are O5-A1 stars and the secondaries occur in the absolutemagnitude range of the Ap stars were, therefore, obtained. Againspectral classification shows no Ap stars in systems with ages notgreater than 1,000,000 yr and a steady increase in Ap stars thereafter.The numerical agreement with the cluster data is good, confirming thatthe cluster data are exhibiting a real age effect.

Radial velocities for early type stars in six galactic regions
Coudespectroscopy has been carried out for 353 stars of spectral typesB0-A0 and V magnitudes between 6.5 and 10.8 m, selected in six regions(three northern and three southern) close to the galactic plane at thegalactic longitudes 135, 175, 315 and 350 deg. The radial velocitieswere obtained by cross-correlating each spectrogram with a referencespectrogram giving an internal error of 1.4 km/s.

Four-color and H-beta photometry for O-A0 type stars in three regions near the galactic equator
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1982A&AS...49..561W&db_key=AST

About the Consistency of Absolute Luminosity Calibrations
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&A....82..370H&db_key=AST

Photometric Study of Trapezium-Type Systems
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1979RMxAA...4..287E&db_key=AST

UVBY photometry of wide visual double stars with B, A and F spectral type- I.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&AS...34..453O&db_key=AST

Catalog of multiple Trapezium type systems
Not Available

UBVRI photometry of stars in Trapezium type systems.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977RMxAA...3..133W&db_key=AST

The kinematics of trapezium systems.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974RMxAA...1..101A&db_key=AST

The classification of intrinsic variable stars. II. The red variables of S and related types
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972ApJ...177..489E&db_key=AST

Catalogue des étoiles mesurées dans le système photométrique de l'Observatoire de Genève
Not Available

Relative Positions and Magnitudes of the Components of Trapezium-Type Stars.
Not Available

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Osservazione e dati astrometrici

Costellazione:Orione
Ascensione retta:04h58m57.20s
Declinazione:+14°32'58.5"
Magnitudine apparente:7.424
Distanza:187.97 parsec
Moto proprio RA:4.2
Moto proprio Dec:-3.2
B-T magnitude:7.484
V-T magnitude:7.429

Cataloghi e designazioni:
Nomi esatti   (Edit)
HD 1989HD 31747
TYCHO-2 2000TYC 697-2145-1
USNO-A2.0USNO-A2 0975-01252115
HIPHIP 23159

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