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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Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS
Radial velocities have been determined for a sample of 2930 B2-F5 stars,95% observed by the Hipparcos satellite in the north hemisphere and 80%without reliable radial velocity up to now. Observations were obtainedat the Observatoire de Haute Provence with a dispersion of 80Ä,mm(-1) with the aim of studying stellar and galactic dynamics.Radial velocities have been measured by correlation with templates ofthe same spectral class. The mean obtained precision is 3.0 km s(-1)with three observations. A new MK spectral classification is estimatedfor all stars. Based on observations made at the Haute ProvenceObservatory, France and on data from The Hipparcos Catalogue, ESA.Tables 4, 5 and 6 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr or viahttp://cdsweb.u-strasbg.fr/Abstract.htm
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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.
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The period and amplitude variations of δ Scuti star HD 93044.
The δ Scuti variable star HD 93044 was observed with the 60cmtelescope at the Xinglong Station of the Beijing AstronomicalObservatory from 1992 to 1993. Period analyses were made for the 1992data set, the 1993 data set, and the combined 1992-1993 data set.Besides the known three frequencies: 11.90809, 16.798 and 22.074c/d, twonew frequencies of 2.086 and 10.489c/d were found. Some amplitudevariations of two pulsation components (11.90809, 22.074c/d) wereobvious. The new frequency of 2.086c/d might be the interaction modefrom which the resonances can occur and then lead to the nonlinearphenomena in the δ Scuti variable star.
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γ Doradus and δ Scuti stars: cousins or twins?
γ Doradus stars are a group of slowly pulsating early F dwarfswith typical low frequencies near 1c/d. The pulsation modes are probablyg modes. These stars are slightly cooler than the typical δ Scutivariables, which pulsate with higher frequencies of typically 10c/d(mostly nonradial p modes). This paper examines the relationship betweenthe two groups of variables. Additional low-frequency variability hasbeen reported for fewer than 10% of the 300 δ Scuti starsexamined. In at least one case (1 Mon), the observational data areconsistent with an alternate interpretation in terms of a modeinteraction, f_1_-f_2_, between two p modes of higher frequency, ratherthan by the excitation of g modes. In several other stars (e.g. 4 CVn),the reported low-frequency variability may originate in the comparisonstar used. Arguments are given that for a number of stars the observedlow-frequency variations are caused by observational errors (such asinstrumental drift and transparency variations). A few δ Scutistars remain for which intrinsic γ Doradus-type variability mayalready have been discovered, although no case is well-studied. One ofthe best candidates is the star BI CMi, which is situated in the smallregion of overlap of the two groups of pulsators in theHertzsprung-Russell diagram. The star deserves further study.
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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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The determination and research of chaotic behavior in δ Sct type stars.
Not Available
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Period analysis of the Delta Scuti star HD93044
HD93044 was observed electrophotometricaly on April 21, May 1, 2 and 4,1991 at Xinglong Station of Beijing Astronomical Observatory. The datawas combined together with Li Zhiping's data and a period analysis wascompleted using a program which consists of a combination of Fouriertranforms of prewhitened data and the multifrequency least squares ofbrightness residuals (LSR). There pulsation frequencies (11.90809,16.79553, 22.44827 cycles per day) with visual amplitudes between 0.0056and 0.0203 mag were found. The solution fits the observations to +0.0071mag which is equal to the mean square deviation of observations. Thefirst frequency (11.90809 cycles per day) must be the right value of thefundamental frequency of HD93044.
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Physical characters of HD 93044
The measurements of uvby H beta of HD 93044 were obtained in April 1991,and the observational results that the star locates nearly in the middleof delta Scuti instability strip with somewhat deviation to red edge.According to Crawford (1979) and Philip's (1979) calibrations, theeffective temperature, absolute visual magnitude and surface gravity areobtained to be Teff = 7300 +/- 200 K, Mv = 1.33mag +/- 0.39 and log g = 3.7 +/- 0.15, respectively. The observationalresults of Delta m1 = 0.01 give an estimate of (Fe/H) =-0.003 +/- 0.18, so the opinion of metallic deficient is not supportedobviously. The observations show the reddening index E(b-y) to be 0.014which is 1.4 times as large as the standard deviation of Crawford's(1979) statistics.
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The Period Analysis of HD93044 and its Amplitude Variations
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993A&A...274..220L&db_key=AST
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The 71st Name-List of Variable Stars
Not Available
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Period analysis of the new Delta Scuti variable HD 93044
Using periodograms for unequally spaced data and convergent leastsquares, 177 differential photoelectric V band measurements of the newlydiscovered Delta-Scuti variable HD 93044 during three nights have beenanalyzed. After resampling the data in equal intervals to check theresults using periodograms for equally spaced data, three frequencies:11.38927, 2.1426 and 22.49097 cycle/d are identified in the data set.The frequencies of 11.38927 and 22.49097 cycle/d indicate that theobserved variability of HD 93044 is due to radial pulsation ofDelta-Scuti type in the fundamental and third overtone modes. Thefrequency of 2.1426 cycle/d is tentatively attributed to an atmosphericextinction effect.
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Geneva photometry of the Delta Scuti star HD 93044
Photometric observations in the Geneva system of the late-A or early-Fgiant HD 93044 show that this star is a Delta Scuti star with apulsation frequency of 11.90808 cycles/day, or a period of 0.0839766day. The amplitude may be somewhat variable, but no second period seemsto be present. The observed pulsation mode is identified with the radialfundamental mode.
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HD 93044: a New delta Scuti Variable?
Not Available
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Radial velocity measurements. I - Ground-based observations of the program stars for the HIPPARCOS satellite
The radial velocities of 272 stars brighter than m(pg) = 8.5 aredetermined by digital microphotometric measurement of plates obtainedwith dispersion 80 A/mm using the Marly slit spectrograph on the 120-cmtelescope of the Observatoire de Haute Provence. The objects wereselected as probable members of the input catalog for the ESA Hipparcosastrometric satellite. The measurement techniques and data-reductionprocedures are described in detail, and the results are presented inextensive tables and graphs and briefly characterized.
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Spectra and colors of A-type stars in a north galactic pole region.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968AJ.....73..152S&db_key=AST
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A finding-list of stars of spectral type F2 and earlier in a north galactic pole region.
Not Available
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INHABITED SKY
