A revised catalogue of delta Sct stars
An extensive and up-dated list of delta Sct stars is presented here.More than 500 papers, published during the last few years, have beenrevised and 341 new variables have been added to our last list, sixyears ago. This catalogue is intended to be a comprehensive review onthe observational characteristics of all the delta Sct stars known untilnow, including stars contained in earlier catalogues together with othernew discovered variables, covering information published until January2000. In summary, 636 variables, 1149 references and 182 individualnotes are presented in this new list. Tables 1 and 2 will be accessibleonly in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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Luminosity and related parameters of δ Scuti stars from HIPPARCOS parallaxes. General properties of luminosity.
The absolute magnitudes of δ Scuti stars derived from parallaxesmeasured by the Hipparcos astrometric satellite are discussed andcompared with the previous estimates based on photometric uvbyβindices. There are significant differences which are related tophotometric effects of metallicity and rotational velocity, but thepossible effect of a close companion on the measured apparent magnitudeshould be also taken into account. The possibility of differentgroupings of δ Scuti stars based on the absolute magnitudes isbriefly discussed. Some high amplitude δ Scuti stars withintermediate or normal metallicity and small and uncertain parallax haveapparently a very low luminosity; this could be a systematic effectrelated to the observational errors.
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Structural Properties of Pulsating Star Light Curves Through Fuzzy Divisive Hierarchical Clustering
Not Available
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A catalogue of variable stars in the lower instability strip.
Identifications, positions, photometry, spectra, some pulsationalfeatures, other astrophysical parameters and literature for 302pulsating variable stars in the lower instability strip, near the ZAMS,are given. About 185 stars have near homogeneous photometric informationin the Stroemgren's uvby-β photometric system. Thiscatalogue/database covers information published until November 1993.
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δ Scuti stars: a new revised list
An extensive and up to date list of δ Sct stars is presented. Thiscatalogue is intended to be a comprehensive review of observationalcharacteristics of all the δ Sct stars known until now, includingstars contained in earlier catalogues together with other new discoveredvariables, covering information published until November 1993. Globalinformation in the form of histograms and diagrams are also shown.
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A homogeneous catalog of new UBV and H-beta photometry of B- and A-type stars in and around the Scorpius-Centaurus OB association
B- and A-type stars in and near the Sco-Cen OB association areinvestigated with UBV and H-beta photometry to acquire data relevant tothe luminosity function of Sco-Cen. The measurements generally consistof two 10-s integrations of U, B, V, (W, N) filters, and theobservations are corrected iteratively for atmospheric extinction andinstrumental response. The data presented give the mean V magnitude,mean B-V, mean U-B, and the estimated uncertainties for these values.The catalog provides a homogeneous catalog of data for a large fieldwith stellar objects delineating membership to the association Sco-Cenand that affect the luminosity function of the aggregate.
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Empirical P-L-C relation for Delta Scuti stars - A catalogue
An extensive and up-to-date list of 192 Delta Scuti stars is presented.Empirical period - luminosity - color (P-L-C) relations are obtained forthe four lowest modes corresponding to radial pulsations. Agreement withpredicted values indicates that, in general, both Stroemgren photometriccalibration and pulsation theory work well for these stars.
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Contributing factors to flux changes in nonradial stellar pulsations
The factors contributing to flux changes in nonradial stellar pulsationsare investigated under conditions applicable to a variety of pulsatingstar types by examining a linearized analytic representation of observedflux changes due to nonradial pulsations with mode indices (l,m).Histograms are presented, showing as a function of l, the relativeimportance of local temperature, geometry, pressure, and limb-darkeningvariations in contributing to nonradial flux changes. A procedure forthe comparison of observational light and color data with modelpredictions on an amplitude ratio versus phase difference plane isoutlined. Application of this procedure to data on Beta Cephei, 53Persei, Delta C Scuti, rapidly oscillating Ap, Cepheid, and ZZ Cetivariables stars is shown to agree with published data on these systems.
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Quasi-160-minute oscillation period of Delta Scuti stars
The resonance power spectrum (or commensurability spectrum) computed for217 Delta Scuti stars indicates that the dominant (most commensurate)period for the total set of oscillation periods of these stars is 162.2+ or - 2.8 min. Within the error limits, this period coincidesapproximately with the 160-min period of global oscillations of the sun.
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Fourier decomposition of the light curves of high amplitude Delta Scuti and SX Phe stars
The light curves of monoperiodic, high amplitude ? Scuti and SXPhe stars have been Fourier decomposed in order to study theirstructural properties. The computed phase differences show a trend toincrease with the period similar to the trend observed in short periodCepheids and RR Lyrae stars. There is some evidence of a separation ofthe light curves in two groups, which indicates the presence of twotypes of pulsation. The proposed separation is discussed taking alsointo account the amplitude-amplitude diagrams, and some comparisons withRR Lyrae star light curves are made. For the present there are noevident physical differences between the stars in the two groups whichcan explain the separation.
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Properties of Am, Delta Del and Delta SCT stars in the VBLUW system
The spread with respect to the main sequence in the two-color diagramsfor 115 Am, Delta Del and Delta Sct, for which VBLUW photometricobservations have been obtained, is primarily attributed to gravityeffects. Exceptions to this rule can be recognized from a comparison oftheir positions in these diagrams and in the reddening-independentdiagram L-U/B-L, where some Delta Sct stars have experienced relativelyhigh reddenings, while others are presumably metal-poor. It is notedthat gravities and temperatures compare satisfactorily with those ofDavis Philip et al. (1976), which were based on uvby-beta photometry.
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Revised list of pulsating stars with ultra-short periods
A comprehensive list of 178 known Delta Scuti and RR Lyrae-stars ispresented. Using this revised list a HR diagram for these ultra shortperiod pulsating stars is plotted and the blue and red edges of theresultant instability strip are determined. Selection effects arediscussed, and the PLC relationship of Breger (1979) is tested usingdata from this list. Stars lying outside the defined instability regionare discussed.
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Simultaneous photometry and radial velocities of dwarf cepheids and Delta Scuti stars
Simultaneous photometry and photoelectric radial velocities arepresented for the dwarf cepheids VZ Cnc, AD CMi, V703 Sco and for thedelta Scuti stars V743 Cen and Rho Pub. Data are presented in tabularform.
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IAU Archives of Unpublished Observations of Variable Stars
Not Available
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Study of the variability of the Delta Scuti-stars. III - Radial and nonradial pulsations in KW 207
Photoelectric observations of the Delta Scuti star KW 207 (HD 73576) arepresented. Despite low variations, the analysis of the light curve showsat least two significant periodicities, which appear to be related tononradial pulsations. It is pointed out that the high rotationalvelocity of KW 207 weakens the hypothesis that among giants thevariables have considerably lower rotational velocities than constantstars.
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Radial and Non-Radial Oscillations in HD 116994 (V743 Cen)
Not Available
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The nature of dwarf Cepheids. V - Analysis and conclusions
The various observational arguments that can be or have been used todetermine the nature of dwarf Cepheids are examined. Three evolutionaryhypotheses are outlined and shown to lead to different expected periodchanges. Despite careful analysis, the derived period changes do notprovide definite information on the evolutionary stage of most of thestars examined. Evidence for the Population I nature of most dwarfCepheids (which are normal delta Scuti stars with large amplitudes) ispresented.
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Comments on the metallicity and frequencies of the Delta Scuti star BDS 1269 A
An argument is presented that the metallicity of BDS 1269 A may benormal. Rucinski's (1978) frequency analysis is repeated with dataprewhitening. The presence of third and fourth frequencies near f_1 =6.35/day is indicated. Comparison is made with other delta Scuti stars.There is no discrepancy between the apparent magnitude difference andabsolute magnitude difference between components A and B of BDS 1269within the errors of the absolute magnitude determination.
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The classification of intrinsic variables. VIII - Ultrashort period Cepheids
The photometric and astrometric data for ultrashort-period Cepheids withmaximum visual magnitudes brighter than 11.5 are collected anddiscussed. Most of these variables are high-mass, little-evolved starswhich, in the halo and disk populations, are blue stragglers. Theluminosities are calibrated from membership in disk and halo populationgroups; the visual magnitude equals 8(1-/c1/sub c) for disk stars, where(C1)sub c is a reddening- and temperature-free parameter.
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Light variability of HD 116994 /V 743 Centauri/
Abstract image available at:http://adsabs.harvard.edu/abs/1979AJ.....84.1211M
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Delta Scuti and related stars
An extensive review is given of the current status of our knowledge ofthe stars in the lower instability strip. Current problems areemphasized. Particular attention is given to the following areas: theconfusion concerning naming and the implied astrophysical properties(often erroneous), single and multiple periods, the effect of rotationand metallicism on pulsation, the nature of the so-called dwarfcepheids, and pulsation in Ap stars. Various reports of unusal andstrange effects are also discussed with personal, possibly biasedjudgment on their reality.
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Intermediate Band and Hbeta Photometry of Ultrashort Period Cepheids
Not Available
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Further Comments on the Period of V743 Cen
Not Available
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On the Light Curve and Period of V743 Cen
Not Available
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UVBY photometry of HD 116994.
Not Available
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UBV photometry of 1 Monocerotis
Abstract image available at:http://adsabs.harvard.edu/abs/1973PASP...85..410M
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Intermediate Band Photometry of BB Lyrae Stars. II. Colors of RR Lyrae and Ultra-Short Period Variables
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973ApJS...25..487J&db_key=AST
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Delta SCT stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&A....23..221B&db_key=AST
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Pulsation of models in the lower part of the cepheid instability strip and properties of AI Vel and del SCT variables.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972A&A....17..367P&db_key=AST
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Short period variable stars. IV. : periods of del SCT stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972A&A....16...38V&db_key=AST
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INHABITED SKY
