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Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
| Searches for OH masers in the circumstellar envelopes of red giant irregular variable stars
Irregular variables of type Lb share many characteristics withasymptotic giant branch (AGB) stars such as Miras and semiregulars(SRs). Despite their large number, irregulars are poorly understood.Using the large Nançay radio telescope, we searched for 18-cm OHmaser emission from these stars. We selected two samples of Lbs thatpresent a noticeable circumstellar envelope. In the first one, 44high-latitude objects with infrared colours of dusty mass-losing starswere observed in a wide-bandwidth velocity-search mode. In addition, 16objects (including six from the first sample), in which othercircumstellar molecular lines had recently been found, were observedwith higher resolution and sensitivity. We did not detect any new OHmaser emission from these samples down to 3σ sensitivity limitsranging from 30 to 200 mJy. We derived upper limits for the efficiencyof a typical pump using far-infrared photons. When compared with knownOH masers in AGB stars, we show that a significant gap is leftunexplored below the threshold that we determined for Lbs. Lowerefficiencies exist in some OH Miras and in the OH SRs. We cannot discardthe possibility of faint OH emission from certain Lbs, based on the sameprocesses as encountered in those sources. We briefly discuss physicalconditions allowing OH emission in the envelope, and the evolutionarystage of objects classified as Lb variables with respect to the AGB.
| 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
| 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).
| Aufsuchkarten fur intrinsic Variable Stars in Brno.
Not Available
| 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.
| 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
| Multiperiodicity in semiregular variables. I. General properties
We present a detailed period analysis for 93 red semiregular variablesby means of Fourier and wavelet analyses of long-term visualobservations carried out by amateur astronomers. The results of thisanalysis yield insights into the mode structure of semiregular variablesand help to clarify the relationship between them and Mira variables.After collecting all available data from various international databases(AFOEV, VSOLJ, HAA/VSS and AAVSO) we test the accuracy and reliabilityof data. We compare the averaged and noise-filtered visual light curveswith simultaneous photoelectric V-measurements, the effect of the lengthversus the relatively low signal-to-noise ratio is illustrated by periodanalysis of artificial data, while binning effects are tested bycomparing results of frequency analyses of the unbinned and averagedlight curves. The overwhelming majority of the stars studied showmultiperiodic behaviour. We found two significant periods in 44variables, while there are definite signs of three periods in 12 stars.29 stars turned out to be monoperiodic with small instabilities in theperiod. Since this study deals with the general trends, we wanted tofind only the most dominant periods. The distribution of periods andperiod ratios is examined through the use of the (log P_0, log P_1) and(log P_1, log P_0/P_1) plots. Three significant and two less obvioussequences are present which could be explained as the direct consequenceof different pulsational modes. This hypothesis is supported by theresults for multiperiodic variables with three periods. Finally, thesespace methods are illustrated by several interesting case studies thatshow the best examples of different special phenomena such as long-termamplitude modulation, amplitude decrease and mode switching.
| Mode switching in the nearby Mira-like variable R Doradus
We discuss visual observations spanning nearly 70 years of the nearbysemiregular variable R Doradus. Using wavelet analysis, we show that thestar switches back and forth between two pulsation modes having periodsof 332d and about 175d, the latter with much smaller amplitude.Comparison with model calculations suggests that the two modes are thefirst and third radial overtone, with the physical diameter of the starmaking fundamental-mode pulsation unlikely. The mode changes occur on atime-scale of about 1000d, which is too rapid to be related to a changein the overall thermal structure of the star and may instead be relatedto weak chaos. The Hipparcos distance to R Dor is 62.4+/-2.8 pc which,taken with its dominant 332-d period, places it exactly on theperiod-luminosity (P-L) relation of Miras in the Large Magellanic Cloud.Our results imply first-overtone pulsation for all Miras which fall onthe P-L relation. We argue that semiregular variables with long periodsmay largely be a subset of Miras and should be included in studies ofMira behaviour. The semiregulars may contain the immediate evolutionaryMira progenitors, or stars may alternate between periods of semiregularand Mira behaviour.
| The Time-Dependence of the Frequency Components in the Light Curve of RV And
The brightness variations of the semiregular variable RV And have beenmonitored for about 12 years at Grinnell College's Grant O. GaleObservatory as part of a project designed to investigate the mode ofpulsation for this class of stars. In the early 1980's the Fourierspectrum of the light curve had only one strong frequency component, butfollowing an apparent mode change in 1986 the Fourier spectrum becamemore complex, suggesting simultaneous pulsation in two or more modes.Since that time both the strengths and the frequencies of thesecomponents have been variable, although there has been a trend backtoward a simpler Fourier spectrum. The behavior of the frequencycomponents suggests that the oscillations of these stars may involvecomplex interactions among several modes of pulsation.
| 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.
| A survey of main-line OH maser emission from semiregular variables.
We have made a high sensitivity (~0.15Jy) search in the OH main-linesfor maser emission from a sample of 181 semiregular variables. OHemission was observed towards five stars. Two new OH lines were detectedand one tentatively. About 10% of semiregulars with distances less than300pc have associated OH maser emission. The OH semiregulars show muchredder near and far infrared colors than similar non-OH stars. On theaverage, their mass loss rates and OH luminosities are slightly lowerthan in the long period Mira variables. Basing on the optical andinfrared properties of the semiregulars and long period variables weconfirmed that properties of the SRa stars are intermediate betweenthose of SRb and Mira variables. The occurrence of strongly polarized,low luminosity OH main-line maser only, together with relatively lowefficiency of pumping by the infrared photons, provides evidence thatthe semiregulars are less evolved than the Mira-type variables. This cansupport the existence of an evolutionary sequence of SRb-SRa-Miravariables. However, the expansion velocities of some OH semiregulars arehigher than those observed in most type I OH Miras and their pulsationalproperties may suggest that they are in a peculiar evolutionary phase.
| Observation of possible mode switching in three semiregular variable stars
Both the amplitude and period of the light variations of the semiregularlong-period variables RV And, S Aql, and U Boo dramaticaly decreased,and then suddenly increased, in recent years. These observations, inconjunction with spectroscopic data, suggest that these stars may haveswitched from fundamental to overtone pulsation and back again.Theoretical models are consistent with both the photometric andspectroscopic observations. The similarity between the longer-periodoscillations of these stars and the behavior of Mira variables supportsthe conclusion that the Miras are fundamental-mode pulsators.
| A Spectrophotometric Study of the Slow Nova V1819 Cygni
Not Available
| RV Andromedae
IAUC 4489 available at Central Bureau for Astronomical Telegrams.IAUC 4489 available at Central Bureau for Astronomical Telegrams.
| A different type of maser star
A systematic survey of short-period, semiregular variable stars has beenmade resulting in the detection of six new water masers. Of the 14short-period maser stars now known, nine are classified as SRbvariables. All are very late spectral type SRb's, typically M7, whilethe overwhelming majority of normal SRb stars is M4 to M6. Their 2.2-11micron color indices are among the lowest of any known maser stars. Theyare presumably less dusty as well. Four of the SRb stars and two of theremainder do not obey the correlation between period and velocity spreadof the emission features that is found for the Mira and long-period,semiregular variables. Finally, high galactic latitudes dominate; 13 ofthe 14 are in excess of 13 deg, and nine of these are greater than 25deg. These facts suggest that the short-period semiregular variables -particularly in SRb stars - may be a very different type of maser starthan the Mira and long-period semiregular variables.
| New variable stars in the region of RV Andromedae.
Not Available
| The kinematics of semiregular red variables in the solar neighbourhood.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972MNRAS.158...23F&db_key=AST
| Observations d'étoiles variables. Années 1946 à 1952
Not Available
| Observations effectuées en 1954
Not Available
| Observations d'étoiles variables à longues périodes ou irrégulières, effectuées par les Membres de l'Association Française d'Observateurs d'étoiles variables et reçues durant les années 1946 à 1952 à l'Observatoire de Lyon
Not Available
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Pozíciós és asztrometriai adatok
| Csillagkép: | Androméda |
| Rektaszcenzió: | 02h11m02.57s |
| Deklináció: | +48°56'45.1" |
| Vizuális fényesség: | 9.972 |
| RA sajátmozgás: | 11.3 |
| Dec sajátmozgás: | -0.7 |
| B-T magnitude: | 12.034 |
| V-T magnitude: | 10.143 |
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