On the Connection Between CWA and RVA Stars
Phase plots of ASAS-3 data of a large number of CWA and RVA variablestars reveal that there is no clear distinction in period or light curveshape between these two types of stars.
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Multiperiodicities from the Hipparcos epoch photometry and possible pulsation in early A-type stars
A selection criterion based on the relative strength of the largestpeaks in the amplitude spectra, and an information criterion are used incombination to search for multiperiodicities in Hipparcos epochphotometry. The method is applied to all stars which have beenclassified as variable in the Hipparcos catalogue: periodic, unsolvedand microvariables. Results are assessed critically: although there aremany problems arising from aliasing, there are also a number ofinteresting frequency combinations which deserve further investigation.One such result is the possible occurrence of multiple periods of theorder of a day in a few early A-type stars. The Hipparcos catalogue alsocontains a number of these stars with single periodicities: such starswith no obvious variability classifications are listed, and informationabout their properties (e.g., radial velocity variations) discussed.These stars may constitute a new class of pulsators.
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Stars with the Largest Hipparcos Photometric Amplitudes
A list of the 2027 stars that have the largest photometric amplitudes inHipparcos Photometry shows that most variable stars are all Miras. Thepercentage of variable types change as a function of amplitude. Thiscompilation should also be of value to photometrists looking forrelatively unstudied, but large amplitude stars.
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Improved Positions of Variable Stars in Northern Pavo
Not Available
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Color Excesses on a Uniform Scale for 328 Cepheids
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1990ApJS...72..153F&db_key=AST
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Circumstellar material and the light variations of RV Tauri stars
Infrared photometry on the JHKL system is given for 35 stars of the RVTauri and related types. The RV Tauri stars show infrared excessesindicating the presence of circumstellar dust with a temperature ofabout 900 K. These dust shells can be equally prominent in oxygen-richor carbon-rich stars; the high carbon content of the latter appears tocounteract the inhibiting effect of their generally lower metalabundance in promoting dust formation. The wide range of energydistributions of RV Tauri stars is attributed in part to differences inthe radial distribution of dust. The RVb stars (whose mean light variescyclically) are redder than the RVa stars (which have constant meanlight), indicating that their dust shells are denser (especially in theinner regions, which radiate strongly in the 1-3 micron band).Far-infrared data reveal cooler dust around some of the stars of groupa. Three W Virginis stars, two of which were already known to showaffinities to the RV Tauri stars, have dust shells. The dust shells forwhich IRAS infrared spectra are available show the 10-micron silicateemission feature regardless of whether the optical spectra are carbon-or oxygen-rich. Some considerations regarding possible models are given.A comparison with the R Coronae Borealis variables has revealedsimilarities.
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A catalogue of field Type II Cepheids
A catalogue of field Type II Cepheids is presented. The primary listconsists of 152 Cepheids sufficiently far from the galactic plane to bevery probably Type II stars. A second list contains 56 additional starsthat are likely, but less certain, Type II Cepheids, including bothstars estimated to be at large distances from the galactic plane butwith uncertain distances and stars close to the galactic plane believedto be Type II for independent reasons.
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Kinematics of field Type II Cepheid variables
The spectra of 49 field Type II Cepheids have been assembled andcombined with 14 additional stars with previously published radialvelocities in order to investigate the kinematics and spectralcharacteristics of these stars. Many of the stars have low peculiarvelocities consistent with circular rotation around the galaxy, whilesome are high-velocity stars. Outside the nuclear bulge, the velocitiesare correlated with photometric metallicities in the sense thatmetal-rich stars show a nearly normal, disklike rotation velocity and alow velocity dispersion. This correlation shows that the low-velocity,metal-rich stars have an old-disk origin. Fewer Cepheids are found inthe field than expected relative to clusters, suggesting a differencebetween the populations of the halo field and clusters. The kinematicproperties of Cepheids in the nuclear bulge appear to be different inthat both metal-poor and metal-rich Cepheids have a high velocitydispersion and show little systematic galactic rotation.
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W Virginis Stars with Properties of RV Tauri Stars
Not Available
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The frequency of Cepheids with companions: a photoelectric approach.
Abstract image available at:http://adsabs.harvard.edu/abs/1977MNRAS.178..505M
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BVI Photometry of Southern Cepheids
Not Available
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VBI photometry of some southern cepheid and RR Lyrae variables
Not Available
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The instability strip of population II cepheids.
Abstract image available at:http://adsabs.harvard.edu/abs/1974AJ.....79..627D
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The light curve parameters of photoelectrically observed galactic Cepheids
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971A&AS....4..265S&db_key=AST
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Galactic Structure and Galactic Rotation from Cepheids.
Abstract image available at:http://adsabs.harvard.edu/abs/1963ApJ...137..249K
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Southern Cepheid Photometry.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1961ApJS....6..253I&db_key=AST
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Le type de population des céphéides galactiques; critères de distinction des types et catalogue
Not Available
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INHABITED SKY
