On the Origin of Long Secondary Periods in Semiregular Variables
The presence of a long secondary period (LSP) in the light curves ofsome local semiregular variables has been known for many years.Furthermore, the LSPs have recently been found in the light curves ofapproximately 25% of the semiregular variables in the LMC. Theytypically have a length of ~500-4000 days, some 5-15 times longer thanthe primary period. Binarity, pulsation, periodic dust ejection, androtation have been suggested as the origin of the LSPs. Here we analyzeechelle spectra of a group of local semiregular variables with LSPs(hereafter LSPVs) in order to try to distinguish between thesesuggestions. In general, we find that LSPVs do not have broader spectralfeatures than semiregulars without a long secondary period (hereafternon-LSPVs). The general upper limit on the equatorial rotation velocityof 3 km s-1 rules out rotating spot and similar models. OneLSPV, V Hya, does have broader spectral lines than similar carbon stars,but it is shown here that rotation alone is not a good model forexplaining the broad lines. Mid-infrared colors of LSPs and non-LSPVsare similar and there are no LSPVs showing the large (60-25) μm IRAScolor exhibited by some R Coronae Borealis (RCB) stars. Thus, there isno evidence for periodic dust ejection from LSPVs. Finally, we find thatthe LSPVs show larger radial velocity variations than non-LSPVs, whichsuggests that LSPs are caused either by binarity or by pulsation. Asimilar conclusion was derived by Hinkle and co-workers.
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Hipparcos red stars in the HpV_T2 and V I_C systems
For Hipparcos M, S, and C spectral type stars, we provide calibratedinstantaneous (epoch) Cousins V - I color indices using newly derivedHpV_T2 photometry. Three new sets of ground-based Cousins V I data havebeen obtained for more than 170 carbon and red M giants. These datasetsin combination with the published sources of V I photometry served toobtain the calibration curves linking Hipparcos/Tycho Hp-V_T2 with theCousins V - I index. In total, 321 carbon stars and 4464 M- and S-typestars have new V - I indices. The standard error of the mean V - I isabout 0.1 mag or better down to Hp~9 although it deteriorates rapidly atfainter magnitudes. These V - I indices can be used to verify thepublished Hipparcos V - I color indices. Thus, we have identified ahandful of new cases where, instead of the real target, a random fieldstar has been observed. A considerable fraction of the DMSA/C and DMSA/Vsolutions for red stars appear not to be warranted. Most likely suchspurious solutions may originate from usage of a heavily biased color inthe astrometric processing.Based on observations from the Hipparcos astrometric satellite operatedby the European Space Agency (ESA 1997).}\fnmsep\thanks{Table 7 is onlyavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/397/997
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Long period variable stars: galactic populations and infrared luminosity calibrations
In this paper HIPPARCOS astrometric and kinematic data are used tocalibrate both infrared luminosities and kinematical parameters of LongPeriod Variable stars (LPVs). Individual absolute K and IRAS 12 and 25luminosities of 800 LPVs are determined and made available in electronicform. The estimated mean kinematics is analyzed in terms of galacticpopulations. LPVs are found to belong to galactic populations rangingfrom the thin disk to the extended disk. An age range and a lower limitof the initial mass is given for stars of each population. A differenceof 1.3 mag in K for the upper limit of the Asymptotic Giant Branch isfound between the disk and old disk galactic populations, confirming itsdependence on the mass in the main sequence. LPVs with a thin envelopeare distinguished using the estimated mean IRAS luminosities. The levelof attraction (in the classification sense) of each group for the usualclassifying parameters of LPVs (variability and spectral types) isexamined. Table only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/374/968 or via ASTRIDdatabase (http://astrid.graal.univ-montp2.fr).
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A library of 0.5 to 2.5 mu m spectra of luminous cool stars
We present a library of 0.5-2.5 mu m digital spectra of cool, mostlyvariable, giant and supergiant stars which should be useful for spectralsynthesis applications, as well as for comparison with theoretical modelatmosphere calculations. The library includes carbon stars, GalacticBulge and Magellanic Cloud stars, and OH/IR stars. The stars observedcover a range of metallicities and masses. Most variable objects wereobserved several times, at different phases of their pulsation cycle. Wediscuss the effects of various fundamental parameters and of variabilityon the spectra. Based on period-luminosity relations and stellarevolutionary tracks, we tentatively assign initial masses to eachobject.
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Period-Luminosity-Colour distribution and classification of Galactic oxygen-rich LPVs. I. Luminosity calibrations
The absolute K magnitudes and kinematic parameters of about 350oxygen-rich Long-Period Variable stars are calibrated, by means of anup-to-date maximum-likelihood method, using Hipparcos parallaxes andproper motions together with radial velocities and, as additional data,periods and V-K colour indices. Four groups, differing by theirkinematics and mean magnitudes, are found. For each of them, we alsoobtain the distributions of magnitude, period and de-reddened colour ofthe base population, as well as de-biased period-luminosity-colourrelations and their two-dimensional projections. The SRa semiregulars donot seem to constitute a separate class of LPVs. The SRb appear tobelong to two populations of different ages. In a PL diagram, theyconstitute two evolutionary sequences towards the Mira stage. The Mirasof the disk appear to pulsate on a lower-order mode. The slopes of theirde-biased PL and PC relations are found to be very different from theones of the Oxygen Miras of the LMC. This suggests that a significantnumber of so-called Miras of the LMC are misclassified. This alsosuggests that the Miras of the LMC do not constitute a homogeneousgroup, but include a significant proportion of metal-deficient stars,suggesting a relatively smooth star formation history. As a consequence,one may not trivially transpose the LMC period-luminosity relation fromone galaxy to the other Based on data from the Hipparcos astrometrysatellite. Appendix B is only available in electronic form at the CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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Stellar radii of M giants
We determine the stellar radii of the M giant stars in the Hipparcoscatalogue that have a parallax measured to better than 20% accuracy.This is done with the help of a relation between a visual surfacebrightness parameter and the Cousins (V - I) colour index, which wecalibrate with M giants with published angular diameters.The radii of(non-Mira) M giants increase from a median value of 50 R_Sun at spectraltype M0 III to 170 R_Sun at M7/8 III. Typical intermediate giant radiiare 65 R_Sun for M1/M2, 90 R_Sun for M3, 100 R_Sun for M4, 120 R_Sun forM5 and 150 R_Sun for M6. There is a large intrinsic spread for a givenspectral type. This variance in stellar radius increases with latertypes but in relative terms, it remains constant.We determineluminosities and, from evolutionary tracks, stellar masses for oursample stars. The M giants in the solar neighbourhood have masses in therange 0.8-4 M_Sun. For a given spectral type, there is a close relationbetween stellar radius and stellar mass. We also find a linear relationbetween the mass and radius of non-variable M giants. With increasingamplitude of variability we have larger stellar radii for a given mass.
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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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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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Semiregular variables of types SRa and SRb. New JHKL'M-photometry for 200 stars.
This paper presents new JHKL'M observations of 200 Semiregular variables(SRVs) of types SRa and SRb. The sample was defined in Kerschbaum &Hron (1992a, Paper I) by means of a certain limit in bolometricalmagnitude. From the sample of 350 objects, 260 now have near infrared(NIR) photometry - for 60 of these stars data from the literature areused. In total 290 datasets are available because of some multipleobservations. We briefly compare the photometry obtained at differentobservatories. Small but significant differences are found. A firstanalysis of the photometry supports one of the main findings of Paper I.The, in many aspects inhomogeneous, O-rich semiregular variables oftypes SRa and SRb can be successfully split in two subgroups called the`blue' and `red'/`Mira' SRVs. A separation of the `red' SRVs fromintrinsic Miras additionally requires variability information.
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On the spectra and photometry of M-giant stars
From a sample of 97 very bright M-giant stars in the Solarneighbourhood, high-quality "intrinsic" spectra in the spectral range380 <~ λ[nm] <~ 900 for all M-spectral subtypes of the Caseand MK classification systems are obtained. The results are fitted tophotospheric synthetic spectra in the range 99 <~ λ [nm]<=12500 in order to infer the corresponding continua. The syntheticspectra are also compared to the intrinsic spectra. The effectivetemperatures are derived and mathematical spectral classificationcriteria are found. The (UB)_j_(VRI)_c_(JHKLM)_ESO_ photometric data ofthe sample are also given. The data are available on the StrasbourgAstronomical Data Centre (CDS).
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Asymptotic giant branch stars near the sun
Available red and near-infrared photometry and apparent motions of M, S,and C asymptotic giant branch (AGB) stars in the Bright Star Catalogueare tabulated and discussed. It is shown that the red and near infraredindices normally used for late-type stars are interchangeable except forcarbon stars. The M-type giants are variable with visual amplitudegreater than 0.05 mag. The reddening-free parameter m2 from Genevaphotometry is essentially a temperature parameter for M giants, whilethe reddening-free parameter d is a sensitive detector of blue stellarcompanions. The space density of AGB stars near the sun decreases by afactor of 35 in a temperature range 3800 to 3400 K. Two of the S starsnear the sun were found to have nearly equal space motions and may becomembers of the Arcturus group.
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Semiregular variables of types SRa and SRb - Basic properties in the visual and the IRAS-range
The pulsational properties, T(eff)s, mass loss rates, luminosities,scale heights, and volume densities in the Galactic plane are presentedfor samples of optical semiregular variables of types SRa and SRbcorrelated with the IRAS point source catalog. These properties arecompared to the corresponding characteristics of optical Mira variables.It is found that the SRa's are not a distinct class of variables but amixture of 'intrinsic' Miras and SRb's. The O-rich SRb's form a quitehomogeneous group in terms of periods, amplitudes, and temperatures.They consist of a 'blue' group with no indication of circumstellarshells, with P less than 150 d and T(eff) greater than 3200 K, and a'red' group with temperatures and mass loss rates comparable to Mirasbut periods about a factor of two smaller. The C-rich SRVs generallyhave smaller periods and are more abundant than C-rich Miras. Theevolutionary status of the SRVs is discussed.
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New low-resolution spectrometer spectra for IRAS sources
Low-resolution spectra of 486 IRAS point sources with Fnu(12microns) in the range 20-40 Jy are presented. This is part of an effortto extract and classify spectra that were not included in the Atlas ofLow-Resolution Spectra and represents an extension of the earlier workby Volk and Cohen which covers sources with Fnu(12 microns)greater than 40 Jy. The spectra have been examined by eye and classifiedinto nine groups based on the spectral morphology. This newclassification scheme is compared with the mechanical classification ofthe Atlas, and the differences are noted. Oxygen-rich stars of theasymptotic giant branch make up 33 percent of the sample. Solid statefeatures dominate the spectra of most sources. It is found that thenature of the sources as implied by the present spectral classificationis consistent with the classifications based on broad-band colors of thesources.
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A second list of wide visual binaries
Not Available
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A second list of wide visual binaries
Not Available
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Variable stars in the General Catalogue of Trigonometric Parallaxes
Not Available
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Polarization measurements of 313 nearby stars
The linear polarization of 313 low galactic latitude stars has beenmeasured. With few exceptions all program stars have a spectral typelater than B9 and are within 600 parsec of the sun. 181 stars aresituated at the southern sky and 132 at the northern sky.
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Kinematical and orbital properties for selected southern high-velocity stars
Using the model of the Galaxy presented by Eggen, Lynden-Bell, andSandage (1962), plane galactic orbits have been calculated for severalsouthern high-velocity stars which possess parallax, proper motion, andradial velocity data. Extensive lists of both raw and computed data forthese stars are included. Published values of U-B and B-V for some ofthese stars were used in plots of each of the orbital parameters versusU-B, B-V, or the ultraviolet excess. Also, a comparison is made betweenthe H-R diagrams for the southern high-velocity star group and that ofM3, a globular cluster, and again for M67, an old open cluster. Thehigh-velocity star group is found to resemble an old open cluster morethan a globular cluster.
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Luminosity functions and the evolution of low-mass population I giants
Luminosity functions in terms of bolometric magnitudes are constructedfor M67 and for two samples of old-disk field giants. These are comparedwith theoretical rates of evolution on the giant branch. M67 has too fewstars to give a useful comparison. The field giants show good agreementwith theory, and the number of stars at the 'clump' suggests that corehelium-burning is prolonged by overshoot with semiconvective mixing. Thefuel consumption derived from the luminosity functions is consistentwith core helium ignition at the theoretically predicted core mass, andwith a final core mass in agreement with observed white dwarf masses.Data are needed for a larger complete sample of field giants for theluminosity function to be better determined. Further details, especiallyfor the variable M giants at the top of the giant branch, are needed forpopulation syntheses of elliptical galaxies.
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59th Name-List of Variable Stars
Not Available
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The classification of intrinsic variables. IV. Very-small-amplitude, very-short-period red variables
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973ApJ...184..793E&db_key=AST
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The classification of intrinsic variable. III. Calibration of the luminosities of small amplitude red variables in the old disk population
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973ApJ...180..857E&db_key=AST
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The ζ Herculis, σ Puppis, ∈ Indi, and η Cephei Groups of Old Disk Population Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971PASP...83..251E&db_key=AST
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Narrow-and broad-band photometry of red stars. VI. Luminosities and temperatures for old disk-population red stars of high luminosity
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971ApJ...165..317E&db_key=AST
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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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Stellar groups, V. Luminosities, motions and masses of the late-type sub-giants
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1960MNRAS.120..430E&db_key=AST
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Stellar groups. II. The ζ Herculis, ɛ Indi and 61 Cygni groups of high-velocity stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1958MNRAS.118..154E&db_key=AST
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Fundamental data for southern stars (First list)
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1957MNRAS.117..534E&db_key=AST
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Stellar parallaxes determined photographically at the Cape Observatory (nineteenth list) Cape of Good Hope, Royal Observatory
Not Available
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INHABITED SKY
