Home     Getting Started     To Survive in the Universe    
Inhabited Sky
    News@Sky     Astro Photo     The Collection     Forum     Blog New!     FAQ     Press     Login  

HD 228911


Contents

Images

Upload your image

DSS Images   Other Images


Related articles

Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available

Einige interessante Bedeckungsveraenderliche.
Not Available

Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics
The Catalogue, available at the Centre de Données Stellaires deStrasbourg, consists of 13 573 records concerning the results obtainedfrom different methods for 7778 stars, reported in the literature. Thefollowing data are listed for each star: identifications, apparentmagnitude, spectral type, apparent diameter in arcsec, absolute radiusin solar units, method of determination, reference, remarks. Commentsand statistics obtained from CADARS are given. The Catalogue isavailable 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/qcar?J/A+A/367/521

UBV beta Database for Case-Hamburg Northern and Southern Luminous Stars
A database of photoelectric UBV beta photometry for stars listed in theCase-Hamburg northern and southern Milky Way luminous stars surveys hasbeen compiled from the original research literature. Consisting of over16,000 observations of some 7300 stars from over 500 sources, thisdatabase constitutes the most complete compilation of such photometryavailable for intrinsically luminous stars around the Galactic plane.Over 5000 stars listed in the Case-Hamburg surveys still lackfundamental photometric data.

A common resonance of delta SCT stars and ellipsoidal binaries.
Not Available

On rotation of ellipsoidal binary systems.
Not Available

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.

Interstellar extinction in the vicinity of the North America and Pelican Nebulae. II
The results of photoelectric photometry of 564 stars in the Vilniusseven-color system in three areas near the North America and PelicanNebulae are given. Photometric spectral types, absolute magnitudes,color excesses, interstellar extinction,s and distances to the stars aredetermined. We find that the dark cloud separating both nebulae is at580 pc distance. A number of stars immersed in the dark cloud have beenfound. It seems that the dark cloud extends south down to 40 degdeclination. The area southwest of alpha Cygni in the declination zones42 deg and 43 deg is comparatively transparent at least up to 1 kpc.

Gravitational radiation and spiralling time of close binary systems. III
Twenty-seven typical binary systems have been investigated to studytheir power-output by gravitational radiation P(B) and spiralling timetau(0) relation. It was found that these binary systems form twodistinct groups. New relations are given between P(B) and tau(0) foreach group.

Errata and supplement to the list of eclipting binaries showing apsidal motion
Not Available

The ellipsoidal variables. IV - Light variations
The Delta(V) variations of ellipsoidal variables are investigated as afunction of the spectral type of the primary. A model is developed onthe assumption that the primary has near main-sequence characteristics.It is argued that the observed minimum in the Delta(V) variations aroundspectral type F is real and is due to variations in thegravity-darkening exponent beta. The absolute upper limit to Delta(V)variations is found to be about 0.2 mag.

The ellipsoidal variables. III - Circularization and synchronization
The degree of orbital circularity and synchronism is employed toestimate the degree of tidal interaction in the ellipsoidal variablesystems. Despite the many varied systems contained under the ellipsoidalvariable classification, most of the orbits are found to be circularizedand synchronized for periods of the variation of the eccentricity ofless than about two. Evolutionary models of the more extreme systems areconsidered.

The ellipsoidal variables
The existing database on ellipsoidal, short period binary star systemsis examined analytically. The survey covers 27 binaries with periods ofno more than 10 days. It is shown that binaries with periods of no morethan 5 days are separated by no more than five times the sum of theirradii, indicating that tidal interactions are nonnegligible. Furthercalculations demonstrate that most short period systems will synchronizetheir orbits during the Main Sequence, then evolve to circular orbits inthe sub-giant phase. The distortions which can be expected along thecenterlines of stars in the Main Sequence is described analytically,noting that the distortion takes the form of an expansion into the Rochelobe. The models are used to generate light curves for suspectedellipsoidal variables, e.g., beta Lyrae, with satisfactory results.Similarly, the spectroscopic signatures of ellipsoidal systems exhibitdual peaked features which vary, a characteristic which can also beunderstood in terms of the filling of the Roche lobe.

The ellipsoidal variable stars
An annotated bibliography is presented for the ellipsoidal variableclass of noneclipsing close binaries, and a method is furnished for theanalysis of the light curves and spectroscopic data to determine thephysical parameters of such systems. Attention is given to confirmedellipsoidal variables, as well as suspected and rejected ones, and tothe characteristics of theoretical ellipsoidal light curves.

Distribution of OB stars and absorbing matter in the region around P CYG
The results of spectrophotometric observations of 277 OB stars in a 7 x7-deg region around P Cyg, obtained in 8-sec, 45-sec, and 8-minexposures on ORWO ZU-21 plates with a 4-deg 272-A/mm-dispersionobjective prism on the 40-in. Schmidt telescope at BiurakanAstrophysical Observatory on October 14-19, 1979, are presented intables and graphs and characterized. Data reported include 400-480-nmabsolute spectrophotometric gradients, color excesses, and distances. Itis found that concentrations of OB stars with associated absorbingmatter exist toward the associations Cyg OB9 (two concentrations at 800and 1800 pc), Cyg OB3 (three concentrations at 1.4, 2.5, and 3.7 kpc),OB1 (at 1.6 kpc), Cyg OB8 (at 1.5 kpc), and over the entire observedregion at a distance of about 500 pc.

Exciting stars and the distances of the diffuse nebulae
Not Available

Statistics of categorized eclipsing binary systems Lightcurve shapes, periods, and spectral types
The statistics of the light curve morphologies, eclipse depths, orbitalperiods, and spectral types of about 1000 eclipsing binary systems areexamined, after attempting to subdivide these binaries into variousbasic evolutionary categories. The applicability of statisticalcriteria, based on light curve morphologies and eclipse depths, for thecategorization of eclipsing binaries has been found more limited thanpreviously believed. In particular, EW-type light curves turn out to begood indicators of contact systems (though not conversely), while EA-and EB-type light curves have little physical significance. Moreover,the study reveals a strong deficit of short-period noncontact systems inthe whole spectral range, together with an underabundance of early-typecontact binaries (compared with the number of late-type contact pairs).Interestingly, the distribution of evolved Algol-type systems isshifted, on average, to periods longer than those of unevolved detachedsystems in the OB and early A spectral range (and to shorter periods inthe F spectral range).

Iterative methods for determination of parameters of spectroscopic binaries
The paper contains the description of iterative methods fordeterminations of geometric and physical parameters of spectroscopicbinaries, especially for computation of orbit plane inclination i andradii of components, which cannot be determined from observations. Thesemethods are based of some considerations given in the previous paper(Dworak 1975). The methods have been tested using data for eclipsingbinaries, taken from the catalogues of Batten et al. (1978) and Koch etal. (1970).

The ellipsoidal binary V470 Cygni
The yellow and blue photoelectric light curves (as yet unsolved) of thedouble lined spectrum binary V470 Cyg (Ebbighausen et al., 1975) areanalyzed by means of the Wilson and Devinney (1971) method. The systemis found to be a detached one, with two almost equal B2-B3 componentsthat do not eclipse each other owing to the very low inclination(approximately 50 deg). It is also found that at primary minimum, thebigger and more massive star is in front. Well-known relations are usedto compute the absolute dimensions of V470 Cyg.

Variable Stars in the Northern Luminous Stars Catalogues
Not Available

Photoelectric Minima of Some Eclipsing Variables
Not Available

Close binary systems before and after mass transfer - A comparison of observations and theory
The paper considers close binary systems before and after mass transfer.Mass, period, and mass ratio distributions and relations of the group of'unevolved' binaries are transformed into corresponding distributionsand relations of evolved binaries. The transformations are based upon arelation derived from an extended set of published computations of theevolution of close binaries. From this relation the characteristics ofinitial parameters after mass exchange are computed and the results werecompared to the observations of binary systems after mass exchange; itis concluded that during mass exchange in close binaries, more than 50%of the mass is lost to the system in the process of transfer, removing alarge amount of angular momentum.

A catalogue of parameters for eclipsing binaries
Not Available

A comparison of the orbital inclinations of the spatially close spectroscopic double stars
The reported investigation takes into account 888 spectroscopicbinaries. It was possible to obtain 120 groups whose elements arespatially close according to the given definition. These 120 groupscontain 313 spectroscopic binaries. 136 of these binaries are 2-spectrumsystems, 177 are 1-spectrum systems, and 62 are eclipsing binaries. Thenumber of systems with known luminosity class is 54. The spectraldistribution of the 313 systems is discussed. The orbital inclinationsand other parameters are presented in a table.

Seventh catalogue of the orbital elements of spectroscopic binary systems.
Not Available

The spectral classification of some stars in the GAM CYG neighbourhood.
Not Available

Photometric observations of V470 Cygni (HD 228911).
Abstract image available at:http://adsabs.harvard.edu/abs/1975PASP...87..923E

MK classifications of some Northern Hemisphere binary systems
Not Available

Strömgren four-colour observations of Northern Hemisphere binary systems
Not Available

Fundamental Data for Massive Stars Compared with Theoretical Models
Abstract image available at:http://adsabs.harvard.edu/abs/1972ApJ...175..431S

Submit a new article


Related links

  • - No Links Found -
Submit a new link


Member of following groups:


Observation and Astrometry data

Constellation:Cygne
Right ascension:20h19m21.71s
Declination:+40°53'16.5"
Apparent magnitude:8.486
Distance:507.614 parsecs
Proper motion RA:-2.9
Proper motion Dec:-7.9
B-T magnitude:8.794
V-T magnitude:8.512

Catalogs and designations:
Proper Names   (Edit)
HD 1989HD 228911
TYCHO-2 2000TYC 3155-265-1
USNO-A2.0USNO-A2 1275-13815701
HIPHIP 100193

→ Request more catalogs and designations from VizieR