Speckle Interferometry of New and Problem HIPPARCOS Binaries
The ESA Hipparcos satellite made measurements of over 12,000 doublestars and discovered 3406 new systems. In addition to these, 4706entries in the Hipparcos Catalogue correspond to double star solutionsthat did not provide the classical parameters of separation and positionangle (rho,theta) but were the so-called problem stars, flagged ``G,''``O,'' ``V,'' or ``X'' (field H59 of the main catalog). An additionalsubset of 6981 entries were treated as single objects but classified byHipparcos as ``suspected nonsingle'' (flag ``S'' in field H61), thusyielding a total of 11,687 ``problem stars.'' Of the many ground-basedtechniques for the study of double stars, probably the one with thegreatest potential for exploration of these new and problem Hipparcosbinaries is speckle interferometry. Results are presented from aninspection of 848 new and problem Hipparcos binaries, using botharchival and new speckle observations obtained with the USNO and CHARAspeckle cameras.
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Classification and Identification of IRAS Sources with Low-Resolution Spectra
IRAS low-resolution spectra were extracted for 11,224 IRAS sources.These spectra were classified into astrophysical classes, based on thepresence of emission and absorption features and on the shape of thecontinuum. Counterparts of these IRAS sources in existing optical andinfrared catalogs are identified, and their optical spectral types arelisted if they are known. The correlations between thephotospheric/optical and circumstellar/infrared classification arediscussed.
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Excitation Mechanism of Molecular Hydrogen Emission in NGC 6240
We have obtained H- and K-band spectra simultaneously in the centralregion of the merging galaxy system NGC 6240. From the observed lineflux ratios of molecular hydrogen (H2) emission, including sensitiveupper limits on highly excited H2 lines, we conclude that the emissionis excited purely by thermal mechanisms. Previously suggestedcontributions of UV fluorescence are negligible, at least in the centralregion. The H2 lines are most likely excited by shocks, nondissociativeor partially dissociative ones, although we cannot rule out completelyX-ray heating. The H2 lines are emitted between the double nuclei. Fromits excitation mechanism and its peak position, we conclude that theemission is from a global shock caused by a galaxy-galaxy collision. Thecomparison between the timescale of the H2 emission and the dynamicaltimescale of the double nuclei suggests that the galaxy-galaxy mergingis in a very early phase, such as would be the case for the first closeencounter.
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Ca II H and K Filter Photometry on the UVBY System. II. The Catalog of Observations
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995AJ....109.2828T&db_key=AST
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Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
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Photometry of Stars in the Field of ZZ Draconis
Not Available
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Photometry for Stars in the Field of V Bootis
Not Available
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Photometry of Stars in the Field of V345 and V553 Aquilae
Not Available
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Photometry of Stars in the Field of the Mira XY Aquilae
Not Available
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Photometry of Stars in the Field of the Mira YZ Draconis
Not Available
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Photometry of Stars in the Field of AV Cygni and DV Cygni
Not Available
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CCD observations of the H-alpha line in late G and K supergiants and their interpretation
CCD echelle spectra of the H-alpha line at 6563 A have been obtained fora sample of 30 G and K supergiants with a spectral resolution of about0.24 A. The data clearly indicate that the observed H-alpha profile is adeep absorption, implying large optical depths in the chromosphere.Also, the line cores are blueshifted in all the stars which suggests thechromospheres are expanding outward. Detailed radiative transfercalculations of H-alpha have been carried out in a spherically symmetricatmosphere with outward-positive velocity and temperature gradients,including explicitly the effects of ionization. The H-alpha lineprofiles have been computed for a wide range of parameters in order toreproduce the observed features of the line. Within the framework of ourmodel, the calculations reinforce the idea that the nonthermalvelocities have to be as large as 25-30 km/s to explain the large widthsof the observed profiles. The rates of mass outflow have been calculatedto lie in the range 10 exp -8 to 10 exp -9 solar mass/yr.
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Search for stars with intrinsic polarization
Results of polarimetric observations of 55 late-type stars arepresented. Twenty of these stars were found to have appreciablepolarization. The dependence of the degree of polarization on wavelengthis given. It is considered very probable that the polarizations of thestars SAO 141881, 141898, and 160413 are intrinsic.
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IRAS catalogues and atlases - Atlas of low-resolution spectra
Plots of all 5425 spectra in the IRAS catalogue of low-resolutionspectra are presented. The catalogue contains the average spectra ofmost IRAS poiont sources with 12 micron flux densities above 10 Jy.
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The stellar component of the galaxy as seen by the AFGL infrared sky survey
The noise-limited magnitudes for the Air Force Geophysical Laboratory(AFGL) Infrared Sky Survey have been estimated by direct comparison withground-based observations. Using these limiting magnitudes, 'pruned'versions of the AFGL catalog have been generated. Infrared observationsof all the stellar objects seen at 11, 20, or 27 microns and astatistical sample of the stars seen only at 4 microns are reported.Analysis of the observations leads to estimates of the absolute 4 and 10microns magnitudes and space densities for the two clases of objects.The expected results from the Infrared Astronomical Satellite arereexamined.
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Narrow-Band and Broad-Band Photometry of Red Stars. III. Southern Giants
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970ApJ...161..199E&db_key=AST
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- and Broad-Band Photometry of Red Stars. Northern Giants
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1967ApJS...14..307E&db_key=AST
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INHABITED SKY
