Садржај
Слике
Уплоадјуј своје слике
DSS Images Other Images
Везани чланци
Semiregular variables in the solar neighbourhood
Period-luminosity sequences have been shown to exist among thesemiregular variables (SRVs) in the Magellanic Clouds, the bulge of theMilky Way galaxy and elsewhere. Using modern-period and revisedHipparcos parallax data, this paper demonstrates that they also appearamong the M giant SRVs of the solar neighbourhood. Their distribution inthe K, logP diagram resembles that of Bulge stars more closely thanthose in the Magellanic Clouds. The prevalence of mass-loss among localM-type SRVs and its dependence on period and spectral subtype are alsodiscussed. K - [12], a measure of circumstellar dust emission, increasesclearly with V amplitude, M giant subtype and logP.
| Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
| 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
| New periodic variables from the Hipparcos epoch photometry
Two selection statistics are used to extract new candidate periodicvariables from the epoch photometry of the Hipparcos catalogue. Theprimary selection criterion is a signal-to-noise ratio. The dependenceof this statistic on the number of observations is calibrated usingabout 30000 randomly permuted Hipparcos data sets. A significance levelof 0.1 per cent is used to extract a first batch of candidate variables.The second criterion requires that the optimal frequency be unaffectedif the data are de-trended by low-order polynomials. We find 2675 newcandidate periodic variables, of which the majority (2082) are from theHipparcos`unsolved' variables. Potential problems with theinterpretation of the data (e.g. aliasing) are discussed.
| 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).
| Periods of 25 Pulsating Red Giants
We report periods and amplitudes of 25 pulsating red giants: T Cet, EGAnd, AK Hya, TV UMa, GK Com, SW Vir, FH Vir, EV Vir, tau-4 Ser, AZ Dra,V973 Cyg, V1070 Cyg, and also HR 211, 284, 648, 2286, 2999, 3521, 4267,4483, 5331, 5352, 6543, 6815, and 7009, determined from AmericanAssociation of Variable Stars (AAVSO) photoelectric photometry over upto 5800 days.
| 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.
| 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.
| Oxygen-rich semiregular and irregular variables
All the known oxygen-rich semiregulars and irregulars of spectralclasses K and M with the absolute value of B not greater than 30 deg,Delta(m) not less than 0.5 mag, and, for the semiregulars, periods inthe range of 50 to 400 d are compiled. On the basis of theirdistributions on the sky and their brightnesses in the K band at 2.2microns, it is argued that the semiregulars with a period of 300-400 dappear to belong to the same population as the 'thin disk' Miras in thesame period range and have an exponential scale height from the Galacticplane of about 250 pc. The semiregulars with a period range of 200 to300 d belong to the population of the 'thick disk' Miras with anexponential scale height from the Galactic plane of about 500 pc. On thebasis of the similarities of their space distributions and the presenceof Tc in their atmospheres, and using the pulsational mode calculationsby Ostlie and Cox (1986), it is suggested that the semiregulars with aperiod range of 100-150 d are first and second overtone pulsations ofthe same population of AGB stars as the Miras in their fundamentalpulsational mode with periods longer than 300 d.
| The SVS Numbering Series Discontinued
Not Available
| The American Association of Variable Star Observers (AAVSO) Photoelectric Photometry Archive
Not Available
| The motions of K and M dwarf stars of different ages
Parallax and proper-motion results are summarized for 145 nearby K and Mdwarfs, and space motions are calculated for most of the sample, whichis not biased toward stars with high velocity. The space motions andtheir U, V, and W components are presented, the mean motion and velocitydispersion of the stars are derived, and the velocity distributions arecompared with previous results. The stars are divided into groupsrepresenting the young-disk, old-disk, and halo populations, and thesizes of the groups are examined along with their kinematicalproperties. The weights of the space motions of the individual starscomprising each group are evaluated by means of a rigorous method basedon the premise that the error in tangential velocity must necessarily bea distance-dependent parameter whereas that in radial velocity is not.The results obtained indicate an outward motion of the young stars withrespect to the old ones and confirm that the kinematical local standardof rest is age-sensitive.
| Parallaxes and proper motions. XII. .
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976AJ.....81.1144W&db_key=AST
| The new identifications of the variable stars with the stars from the "Two-Micron Sky Survey - a preliminary catalog" by G. Neugebauer et al. (IRC).
Not Available
| Observations d'étoiles variables rouges irrégulières
Not Available
|
Додај нови чланак
Линкови у сродству са темом
Додај нови линк
Чланови следећих група \:
|
Посматрања и Астрометриски подаци
| Сазвежђа: | Змај |
| Ректацензија: | 16h40m42.52s |
| Deклинација: | +72°40'18.0" |
| Apparent магнитуда: | 7.024 |
| Даљина: | 467.29 parsecs |
| Proper motion RA: | 5.2 |
| Proper motion Dec: | 5.9 |
| B-T magnitude: | 9.056 |
| V-T magnitude: | 7.192 |
Каталог и designations:
|
