Long-term monitoring of active stars. IX. Photometry collected in 1993
As a part of an extensive program focused on the global properties andevolution of active stars, high-precision UBV(RI)_c and UBV photometryof 31 selected stars is presented. The UBV(RI)_c observations werecollected at the European Southern Observatory over the 31 December1992-18 January 1993 and the 20 November-3 December 1993 intervals.Additional UBV photometry obtained by the ``Phoenix" and by the CataniaAstrophysical Observatory Automatic Photoelectric Telescopes from 1990to 1993 is also presented for some of the program stars. Significantevolution of the light curves, period variations and evidence forlong-term variability of the global degree of spottedness are found.Some spectral classifications are revised and the inferred photometricparallaxes are compared, whenever possible, with the values measured bythe Hipparcos satellite. These observations are finalized to theconstruction of an extended photometric database, which can giveimportant clues on topics such as the stability of spotted areas,differential rotation, solar-like cycles and the correlation betweeninhomogeneities at different atmospheric levels. Based on data collectedat the European Southern Observatory, La Silla, Chile. Tables and thecomplete data set are also 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/367/910
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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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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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Absolute photometry of the southern Orion region in the vacuum ultraviolet (1300-2000 A)
Absolute photometry of the southern Orion region was carried out forfive passbands in the vacuum ultraviolet (1300-2000 A, Delta Lambda = 84A) with a rocket-borne spectrometer. More than 60 early-type stars andthe diffuse background radiation were observed within the raster-scannedfield of 8 x 8 deg centered at alpha = 5 h 30 m and delta = -4 deg.Stellar data suggest a revision of the current absolute scale by 10-30percent, which relatively suppresses the flux toward shorterwavelengths. The present data of the background radiation have thehighest spectral resolution among those published and indicate a steepsystematic increase of the flux toward shorter wavelengths. Directconsequences of the new calibration are briefly discussed.
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Ultraviolet spectrophotometry of some stars in the association Orion OBI
Not Available
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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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A photometric study of the Orion OB 1 association. III - Subgroup analyses
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978ApJS...36..497W&db_key=AST
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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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Interstellar extinction in the Orion association
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968ApJ...152..913L&db_key=AST
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Classificazione spettrale con prisma obiettivo di stelle del complesso Orione
Not Available
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Two-Dimensional Spectral Classification by Narrow-Band Photometry for B Stats in Clusters and Associations.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1958ApJ...128..185C&db_key=AST
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Catalogue of stars in the area of the Orion Nebula.
Not Available
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A Study of the Orion Aggregate of Early-Type Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1952ApJ...116..251S&db_key=AST
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