A catalog of rotational and radial velocities for evolved stars. II. Ib supergiant stars
Rotational velocity vsin i and mean radial velocity are presented for asample of 231 Ib supergiant stars covering the spectral region F, G andK. This work is the second part of the large survey carried out with theCORAVEL spectrometer to establish the behavior of the rotation for starsevolving off the main sequence (De Medeiros & Mayor 1999). Thesedata will add constraints to the study of the rotational behavior inevolved stars, as well as solid information concerning tidalinteractions in binary systems and on the link between rotation,chemical abundance and activity in stars of intermediate masses. Basedon observations collected at the Haute-Provence Observatory,Saint-Michel, France and at the European Southern Observatory, La Silla,Chile Table 1 is 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/395/97
|
Sodium enrichment of stellar atmospheres. I. Non-variable supergiants and bright giants
48 supergiants and bright giants have been observed in order toinvestigate the sodium enrichment of their atmospheres and itsconnection with stellar gravity. We present the equivalent widths of the6154 Å and 6160 Å Na I lines measured from the programspectra, the results of effective temperature determinations, the NLTEsodium abundances, and the derived relation between the sodiumoverabundance and surface gravity.
|
Speckle Interferometry of New and Problem Hipparcos Binaries. II. Observations Obtained in 1998-1999 from McDonald Observatory
The Hipparcos satellite made measurements of over 9734 known doublestars, 3406 new double stars, and 11,687 unresolved but possible doublestars. The high angular resolution afforded by speckle interferometrymakes it an efficient means to confirm these systems from the ground,which were first discovered from space. Because of its coverage of adifferent region of angular separation-magnitude difference(ρ-Δm) space, speckle interferometry also holds promise toascertain the duplicity of the unresolved Hipparcos ``problem'' stars.Presented are observations of 116 new Hipparcos double stars and 469Hipparcos ``problem stars,'' as well as 238 measures of other doublestars and 246 other high-quality nondetections. Included in these areobservations of double stars listed in the Tycho-2 Catalogue andpossible grid stars for the Space Interferometry Mission.
|
Colour excesses of F-G supergiants and Cepheids from Geneva photometry.
A reddening scale for F-G supergiants and Cepheids is presented.Supergiants with low reddenings or in clusters form the basis of thecalibration. In this sense, it is entirely empirical. The data have beenobtained in the Geneva photometric system. Comparisons with otherreddening scales show no disagreement. The only problem is with Fernie'sscale for Cepheids (1990), where a systematic trend exists. Its originis not clear. It is suggested to extend the number of supergiants withindependently obtained colour excesses in order to test the existence ofa possible luminosity dependence of the calibration. A period-colourrelation for Cepheids is deduced, on the basis of the present reddeningcorrections. It gives strong support for V473 Lyr being a secondovertone pulsator.
|
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.
|
The southern Vilnius photometric system. I - Transformation to the standard system
This paper is the first in a series on the extension of the Vilniusphotometric system to the southern hemisphere. Observations of a commonset of 73 stars measured in both hemispheres are described and ananalysis of the differences is given.
|
Multifrequency comparison of Cepheids and nonvariable supergiants
New IUE data and infrared J, H, K, L, and M observations have beenobtained for nonvariable yellow supergiants and the prototype classicalCepheid Delta Cephei. These data have been combined with data in theliterature to make a comparison between nonvariable yellow supergiantsand Delta Cephei from the UV through the near-IR. The supergiantsequence shows a smooth progression of energy distributions withspectral type over this extended wavelength range. The Delta Cepheienergy distributions on the descending branch of the light curve(free-fall portion of the pulsation curve) are well matched bysupergiant energy distributions with the same (B-V)(0) for most phases.At the hottest phases, however, there is some extra flux at 3000 A ascompared with the nonvariables. The Delta Cephei observation on theascending branch of the light curve ('piston' phase of the pulsationcycle) has slightly more UV light than would be predicted from eitherthe supergiant observations or the free-fall Delta Cephei phases.
|
A photometric study of the G0-4 Ia(+) hypergiant HD 96918 (V382 Carinae)
Using a photometric method we derive T(eff), log g, and E(B-V) for thestar HD 96918 and also for 35 supergiants of similar spectral class. ForHD 96918 we found T(eff) = 5200 +/- 200 K and log g (cm/sq s) = 0.0 +/-0.5. The comparison of the results indicates that HD 96918 is really ahypergiant with a spectral class around G0-G4. We also estimate thedistance of HD 96918 using the kinematic and reddening methods, and bycomparing its T(eff) and log g with evolutionary calculation. Weconsistently find a distance of 2.7 +/- 1.0 kpc which implies logL/solar luminosity = 5.5 +/- 0.4. A most probable mass for the star is20 +/- 10 solar mass.
|
The Perkins catalog of revised MK types for the cooler stars
A catalog is presented listing the spectral types of the G, K, M, and Sstars that have been classified at the Perkins Observatory in therevised MK system. Extensive comparisons have been made to ensureconsistency between the MK spectral types of stars in the Northern andSouthern Hemispheres. Different classification spectrograms have beengradually improved in spite of some inherent limitations. In thecatalog, the full subclasses used are the following: G0, G5, G8, K0, K1,K2, K3, K4, K5, M0, M1, M2, M3, M4, M5, M6, M7, and M8. Theirregularities are the price paid for keeping the general scheme of theoriginal Henry Draper classification.
|
Observational evidence for mass loss from classical Cepheids
This paper examines the evidence for mass loss from classical Cepheidvariables in the light of recent observational studies of infrared andultraviolet emission from these objects. Mass-loss rates derived forseveral stars range between 10 to the -10th solar masses/yr and 10 tothe -6th solar masses/yr. The lower end of this range probablycorresponds to the majority of classical Cepheids. Nonvariablesupergiants show, on average, a somewhat lower rate of infrared excess,but have mass-loss rates of the same order of magnitude as the Cepheids.On the basis of the observations to date, mass loss alone isinsufficient in explaining the Cepheid mass discrepancy, indicating thatadjustments to the evolutionary or pulsation models present a betterprospect of resolving this discrepancy.
|
A photometric determination of the metal content for F-G type supergiants in the Large Magellanic Cloud
A VBLUW photometric analysis is used to derive the metal content of some100 F- and G type supergiants in the LMC. Using the empirical locus ofPel in the V-B/B-L diagram in conjunction with the relative dependenceof theoretical colors on the metal abundance, a metal deficiency of1.4-1.6 is found for the LMC stars in comparison with those in the solarneighborhood. With an average UBV system foreground reddening of E(B-V)= 0.05 for the LMC, these stars have a metal content of 0.66 + 0.11,-0.03 of the solar abundance. Agreement is found with the result ofprevious studies. Application to the derivation of the reddenings ofmost of the galactic supergiants is noted.
|
New UBVRI photometry for 900 supergiants
A description is presented of the results obtained in connection with asystematic program of supergiant photometry on the Johnson UBVRI system.During the eight years after the start of the program, almost 1000 starshave been observed, about 400 three or more times each. The originalselection of stars used the spectral type catalog of Jaschek et al.(1964) to choose supergiants. Since observations were possible from bothChile and Canada, no declination limits were imposed, and no particularselection criteria were imposed other than to eliminate carbon stars.These are so red as to require enormous extrapolations of thetransformation equations.
|
Nineteen new spectroscopic binaries and the rate of binary stars among F-M supergiants
Nineteen spectroscopic binaries (SBs) have been discovered in radialvelocity measurements made with the CORAVEL spectrophotometer on 181northern F-M supergiants. The rate of detected SBs among northern F-Msupergiants is 21 percent, without any dependence on spectral orluminosity class. The study of the binary F-M supergiants with knownorbital elements indicates that all the systems with a period smallerthan the critical value P(circ) have a nearly circular orbit. The valueof P(circ) depends on the luminosity class, being 400-600 d for class Iband 2000-7000 d for class Ia. This circularization of the orbits may bedue to the transfer of angular momentum during the phase of binary massexchange.
|
Five-channel photometry of cepheids and supergiants in the southern Milky Way.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976A&AS...24..413P&db_key=AST
|
Photometric data for 139 supergiants.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972AJ.....77..150F&db_key=AST
|
On the Existence of Stable Stars in the Cepheid Instability Strip
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971ApJ...168..437F&db_key=AST
|
The space distribution and kinematics of supergiants
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970AJ.....75..602H&db_key=AST
|
Narrow band photometry in the study of stellar populations. I. The sodium D lines in late-type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1966MNRAS.134..135P&db_key=AST
|
UBV photometry of 550 F, G and K type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1966MNRAS.133..475A&db_key=AST
|
Color Excesses for Supergiants and Classical Cepheids.VI. on the Intrinsic Colors and the Hess Diagram of Late-Type Supergiants.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1961ApJ...134..850K&db_key=AST
|
Color Excesses from Six-Color Photometry of Supergiant Stars
Not Available
|
Spectral Classification of Stars Noted on Case Objective-Prism Plates. I
Not Available
|
A Finding List of F Stars of High Luminosity.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1952ApJ...115..475N&db_key=AST
|
INHABITED SKY
