VRI photometry of wide double stars with A- type primaries.
We are presenting VRI photometry of 93 wide visual double stars havinglate B- or A- type primaries, taken from the Annex of Double andMultiple Stars of the HIPPARCOS Input Catalogue. Spectral types havebeen estimated for most of the primaries and for the majority of thesecondaries. 40% of them probably have common origin components, forwhich we calculated photometric parallaxes and some orbital valuesestimates.
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A search for Lambda Bootis stars in OB associations
A search for Lambda Bootis stars in two OB associations, Orion OB1 andLacerta OB1, has been carried out. One Lambda Bootis star has beendiscovered in the Orion OB1 association. In addition, nine A-type starswhich appear to be slightly metal weak have been found in the twoassociations. The Lambda Bootis star is situated on the Zero-Age MainSequence (ZAMS). The discovery of these stars strengthens the hypothesisthat the Lambda Bootis stars are related to a short-lived evolutionaryphase associated with the arrival of the star on the ZAMS.
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Machine-readable version of the Parenago catalogue of stars in the area of the Orion nebula
Not Available
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Walraven photometry of nearby southern OB associations
Homogeneous Walraven (VBLUW) photometry is presented for 5260 stars inthe regions of five nearby southern OB associations: Scorpio Centaurus(Sco OB2), Orion OB1, Canis Major OB1, Monoceros OB1, and Scutum OB2.Derived V and (B - V) in the Johnson system are included.
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A complex investigation of the star formation region in the Orion constellation
The proper motions of 54 young stars in the Ori OB1 cluster are refined.Cluster contraction with a characteristic time of 3 x 10 to the 6th yris found as well as cluster rotation with a period of 6 x 10 to the 6thyr. A cluster velocity of -10 km/s is determined from the spatialvelocities of 26 stars, indicating that about 1.4 x 10 to the 7th yrago, the cluster was situated in the Galactic symmetry plane; thiscoincides with the age of the oldest subcluster of the association.
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Photometric variability of some CP stars
The photometric data relative to twenty-three southern CP stars havebeen re-analyzed. New or improved parameters of the lightcurves arepresented for eleven of them.
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A catalogue of stellar spectrophotometric data
A list of 378 sets of stellar energy distributions for 356 stars basedon photoelectric spectrophotometry is presented. Data from eight sourceshave been transformed to the Hayes-Latham calibration of Alpha Lyrae.The procedure follows that of Breger (1976) and the present list extendsprevious data, especially for stars of earliest and intermediatespectral types.
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Two sparse open clusters in the region of Collinder 132.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977PASP...89..803C&db_key=AST
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Spectral types in the ORI OB1 association.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977PASP...89..797A&db_key=AST
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A photometric study of the Orion OB 1 association. I - Observational data.
A catalog of observational data is presented for stars in the region ofthe young stellar association Orion OB 1. Photoelectric observationsobtained in the uvby-beta and UBV systems are compiled along withprevious photoelectric and spectroscopic data for all these stars aswell as for several bright members of the association with availablephotometric indices. Mean weighted values are computed for thephotometric data and summarized in tables expected to be reasonablycomplete for association members earlier than spectral type A0.Membership criteria are derived, and qualitative membershipprobabilities summarized, for the 526 stars in the final program. Theanalytical procedures are discussed for association stars of B,intermediate, and AF types. Effects of the nebular environment andvarious calibrations of Balmer-line and four-color indices areconsidered for the determination of absolute magnitudes for the B-typestars.
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UVBY BET photometry of equatorial and southern bright stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977A&AS...27...47H&db_key=AST
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Classificazione spettrale con prisma obiettivo di stelle del complesso Orione
Not Available
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Catalogue of stars in the area of the Orion Nebula.
Not Available
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INHABITED SKY
