Time Variability of the Ca II K Emission Line of Giants
This paper reports the results of a program to search for evidence oftime variability in the profile of the central emission component of theCa II K line of a sample of Population I field giant stars. Highresolution spectra of this line have been obtained using echelle andcoudé spectrographs on the 82-inch (2.1-m) and 107-inch (2.7-m)telescopes of McDonald Observatory. Data are drawn from previous papersof Smith & Shetrone and combined with new observations obtainedduring the period 2004-2007 to give multiple observations for a sampleof 31 evolved giant stars extending over the period 1998-2007. Theasymmetry of the Ca II & lt; 1.0.
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Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
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New observations of H_2 vibrational fluorescence in NGC2023
The Canada-France-Hawaii Telescope has been used to obtain images ofNGC2023 in the 1-0 S(1) and 1-0 S(2) lines of vibrationally excitedH2 at 2.121 mu m and 2.033 mu m, respectively, at a spatialresolution of 0.8". Images show the presence of widespread emissionexhibiting structure on a milliparsec scale. Using the latest estimatesof the VUV field of the exciting star HD37903, steady-statephotodissociation region (PDR) models are able to reproduce thebrightness of the observed emission with good accuracy, showing that thenumber density in the emitting region is ~ 10(5) cm(-3) .
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NGC 1978 in the LMC: the cluster and surrounding field.
We present deep BVRI CCD photometry of the Large Magellanic Cloudcluster NGC 1978 and of fields immediately to the west. From the studyof the colour-magnitude diagram and the luminosity function we derivefor NGC 1978 an age of slightly more than 2Gyr and a metallicity of[Fe/H]=-0.4. NGC 1978 is, for a globular cluster, rather ellipticalwhich had been explained by a merger origin. No age structure inside NGC1978 was found, which limits this possibility to a merger of roughlycoeval subunits. In the field indications for a higher star formationrate at 1x10^8^ and 6x10^8^yr exist 8' west of the cluster, while nosuch phases can be found near the cluster. At ages older than 2Gyr thestar formation rate appears to have been the same in all analysedfields. On a broader scale, NGC 1978 seems to be one of the oldest ofthe LMC intermediate age clusters. A coherent redetermination of theages of the oldest clusters of this age group underlines a suddenenhancement of the cluster formation rate in the LMC about 2 Gyr ago.
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Analysis of Neckel and Chini standard stars in the UBVRI photometric system
This paper studies the list of 60 faint standard stars of Neckel andChini (1980) in the UBVRI Johnson photometric system. We have re-reducedthe standard stars using our own method of reduction from a large numberof selected observations made at the Observatorio Astronomico Nacionaland at the Centro Astronomico Hispano-Aleman, both at Calar Alto, Spain,and at the Observatorio del Roque de los Muchachos, La Palma Island,Spain. The reduction method used is explained and the results are givenfor the four colors used: (B-V), (U-B), (V-R), and (V-I), together withthe V magnitude, that is, we have corrected many standard stars for eachcolor and magnitude. These results are supported with graphs whereresidual color is plotted against corresponding color (or magnitude).Finally, our (V-R) and (V-I) results are compared to those of Taylor etal. (1989), with a good correspondence.
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Broad-band photometry of infrared luminous quasar IRAS 00275-2859
CCD BVRI and near infrared JHKL' observations of the infrared luminousquasar IRAS 00275-2859 are presented in this paper. Combined with thedata from IRAS and radio bands, it is found out that its energydistribution is different from the one of the first infrared quasar IRAS13349 + 2438, but close to that of typical quasars. It is reasonable toconsider that the radiation from IRAS 00275-2859 in radio, infrared, andoptical regions is mostly nonthermal. In addition, we get M(B) = -23.14,far-infrared luminosity L(IR) = 1.58 x 10 exp 12 solar, and L(IR)/L(B)about 10 for IRAS 00275-2859.
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Catalog of mean stellar radial velocities (catalog on magnetic tape)
A catalog of the mean radial velocities for 6451 Galactic stars isdescribed, which supplements the General Catalogs of Wilson (1953) andEvans (1978) with published observations up to December, 1980. Onlyobservations with adequate spectral resolution and standardized to theIAU or Wilson velocity systems are included in the catalog. The accuracyand sources of the data, and the weighting system used in constructingthe catalog are discussed. A sample section of the catalog is presentedand explained.
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The properties of the Neckel-Chini VRI system
Cousins (1980) data for 54 of the standard stars of Neckel and Chini(1980) and published measurements are used to investigate the propertiesof the Neckel-Chini VRI system. For red stars, this system diverges fromthe Johnson (1962) system, despite frequent claims of identity betweenthe two. The Neckel-Chini and Cousins systems, however, are closelycomparable. Both of these conclusions were previously reached in a paperby Bessell (1983); fair to good quantitative agreement with his resultsare obtained. Reddening ratios, the scatter in the Neckel-Chinistandard-star data, and the effect of this scatter on publishedmeasurements for program stars, are discussed. Transformations from theNeckel-Chini system to the Cousins system are given.
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Sixty faint UBVRI standards
A list of 60 faint UBVRI standards is presented. Their UBV magnitudesare in the system introduced by Johnson (1955) and their V-R and V-Icolors are in the system of the Arizona Tonantzintla catalogue byIriarte et al. (1965). These stars are spread over an equatorial belt atan angle less than 30 deg, so that they can be observed as well fromnorthern as from southern sites.
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Radial Velocities and Spectral Classification of A-Type Stars Near the South Galactic Pole
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971PASP...83..643B&db_key=AST
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A finding list of early-type stars near the south galactic pole.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971AJ.....76..338S&db_key=AST
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Three-colour photometry of early-type stars near the galactic poles
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1963MNRAS.127...83W&db_key=AST
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Rotational velocities of faint stars of early spectral types.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1963AJ.....68..428S&db_key=AST
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