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Golden Ratio Sinusoidal Sequences and the Multimode Pulsation of the δ Sct Star V784 Cassiopeiae
Non periodic ordered sequences obtained by production rules in formalgrammars are applied to the analysis of the multi-periodicity of theδ-Scuti type variable star V784 Cas. An artificial light curvefor V784 Cas is generated by a non deterministic derivation in acontext-sensitive grammar by concatenation of two sinusoidal fragmentsfollowing certain word sequences. The two basic building blocksrepresent temporal segments in a golden ratio and the number of long andshort segments in a word are also in a golden ratio.
| Observations of Star-Forming Regions with the Midcourse Space Experiment
We have imaged seven nearby star-forming regions, the Rosette Nebula,the Orion Nebula, W3, the Pleiades, G300.2-16.8, S263, and G159.6-18.5,with the Spatial Infrared Imaging Telescope on the Midcourse SpaceExperiment (MSX) satellite at 18" resolution at 8.3, 12.1, 14.7, and21.3 μm. The large angular scale of the regions imaged (~7.2-50deg2) makes these data unique in terms of the combination ofsize and resolution. In addition to the star-forming regions, twocirrus-free fields (MSXBG 160 and MSXBG 161) and a field near the southGalactic pole (MSXBG 239) were also imaged. Point sources have beenextracted from each region, resulting in the identification over 500 newsources (i.e., no identified counterparts at other wavelengths), as wellas over 1300 with prior identifications. The extended emission from thestar-forming regions is described, and prominent structures areidentified, particularly in W3 and Orion. The Rosette Nebula isdiscussed in detail. The bulk of the mid-infrared emission is consistentwith that of photon-dominated regions, including the elephant trunkcomplex. The central clump, however, and a line of site toward thenorthern edge of the cavity show significantly redder colors than therest of the Rosette complex.
| The multimode pulsation of the delta Scuti star V784 Cassiopeae
We present an analysis of new Johnson and Strömgren photometric andmedium-resolution spectroscopic observations of the delta Scuti typevariable star V784 Cassiopeae. The data were obtained in threeconsecutive years between 1999 and 2001. The period analysis of thelight curve resulted in the detection of four frequencies ranging from9.15 d-1 to 15.90 d-1, while there is a suggestionfor more, unresolved frequency components, too. The mean Strömgrenindices and Hipparcos parallax were combined to calculate the followingphysical parameters: < T_eff >= 7100 +/- 100 K, log g= 3.8 +/-0.1, M_bol= 1\fm50 +/- 0\fm15. The position of the star in the HRdiagram was used to derive evolutionary mass and age yielding to aconsistent picture of an evolved delta Scuti star with a mixture ofradial plus non-radial modes. Based on spectroscopic data obtained atthe David Dunlap Observatory, University of Toronto and photometricobservations obtained at the Sierra Nevada Observatory, IAA-CSIC.
| On the Variability of A0-A2 Luminosity Class III-V Stars
We study the Hipparcos Satellite photometry of A0-A2 luminosity classIII-V stars. Most are not particularly variable. A few stars for whichfurther study is desirable are identified.
| Absolute proper motions of open clusters. I. Observational data
Mean proper motions and parallaxes of 205 open clusters were determinedfrom their member stars found in the Hipparcos Catalogue. 360 clusterswere searched for possible members, excluding nearby clusters withdistances D < 200 pc. Members were selected using ground basedinformation (photometry, radial velocity, proper motion, distance fromthe cluster centre) and information provided by Hipparcos (propermotion, parallax). Altogether 630 certain and 100 possible members werefound. A comparison of the Hipparcos parallaxes with photometricdistances of open clusters shows good agreement. The Hipparcos dataconfirm or reject the membership of several Cepheids in the studiedclusters. Tables 1 and 2 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| 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.
| Catalog of BV magnitudes and spectral classes of 6000 stars
The present catalog, compiled at the Abastumani Observatory, contains BVmagnitudes and spectral classes of about 6000 stars up to V(lim) = 13.0min five circular areas of 18 sq deg located near the salactic-equatorplane. The catalog is intended for star-statistics studies ofstar-formation regions.
| A spectrophotometric survey of stars along the Milky Way. IV
In the present paper a catalogue of spectrophotometric quantities,spectral types, monochromatic magnitudes and colour equivalents is givenfor all stars brighter than the magnitude m4400 = 10.5 in aregion of the Milky Way in Perseus. No absorption is found for starscloser than about r = 100 pc. The absorbing clouds are situated atdistances closer than 1 kpc and at about 2.5 kpc in the local arm andthe Perseus arm, respectively. The space between the two arms is freefrom absorption. It is also concluded that the Perseus arm continuesbeyond l = 140 deg, containing not only hydrogen gas but also dust to atleast l = 150 deg), while the content of OB stars decreases abruptly atl = 140 deg.
| An A-stars concentration in Cas.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974AJ.....79..116P&db_key=AST
| The space density of A stars in a region in Cas.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974AJ.....79..107M&db_key=AST
| Photometric and Polarimetric Observations of the Nearby Strongly Reddened Open Cluster Stock 2
Abstract image available at:http://adsabs.harvard.edu/abs/1967ApJ...147..988K
| Etude pour chaque champ de l'absorption et de la repartition des vitesses radiales EN fonction de la distance.
Not Available
| La mesure des vitesses radiales au prisme objectif - X - 4e liste de vitesses radiales déterminées au prisme objectif à vision directe
Not Available
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