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HD 238987


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SB9: The ninth catalogue of spectroscopic binary orbits
The Ninth Catalogue of Spectroscopic Binary Orbits(http://sb9.astro.ulb.ac.be) continues the series of compilations ofspectroscopic orbits carried out over the past 35 years by Batten andcollaborators. As of 2004 May 1st, the new Catalogue holds orbits for2386 systems. Some essential differences between this catalogue and itspredecessors are outlined and three straightforward applications arepresented: (1) completeness assessment: period distribution of SB1s andSB2s; (2) shortest periods across the H-R diagram; (3)period-eccentricity relation.

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.

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 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.

The period distribution of unevolved close binary systems
Period distributions have been examined for various spectral types ofabout 600 (eclipsing and spectroscopic) close binaries, which are likelyto be substantially unevolved. The comparison with the previouscorresponding analyses of extensive (but heterogeneous) binary samplesallows a clarification of the extent of the evolutionary andobservational selection effects. Remarkably, this analysis reveals agreat deficiency of short period binaries (with periods corresponding tocase A mass transfer) in the whole spectral range. For the late spectraltypes, this result may be connected with postformation angular momentumloss caused by stellar wind magnetic braking; at least for the late Band A spectral range, a ready interpretation of this finding is thatclose binaries of corresponding periods and spectral types are rarelyformed.

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).

64th Name-List of Variable Stars
Not Available

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

The Ellipsoidal System BD +56°2190
Abstract image available at:http://adsabs.harvard.edu/abs/1974PASP...86..677B

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관측 및 측정 데이터

별자리:용자리
적경:19h05m03.38s
적위:+57°07'32.4"
가시등급:9.285
적경상의 고유운동:12
적위상의 고유운동:56.4
B-T magnitude:9.622
V-T magnitude:9.313

천체목록:
일반명   (Edit)
HD 1989HD 238987
TYCHO-2 2000TYC 3927-296-1
USNO-A2.0USNO-A2 1425-09461482
HIPHIP 93727

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