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X-Ray Counterparts of Runaway Stars
An X-ray search for possible compact companions of runaway OB stars hasbeen conducted using pointed ROSAT observations. Of a list of 71 runawaystars, ROSAT exposures were available for 24, of which 13 are detected.These numbers are nearly 3 times larger than for a previously studiedEinstein sample, and spectral information is exploited as well.Luminosities, hardness ratios, and long-term variability are as fornormal OB stars and do not suggest the presence of collapsed companions.A result like this is often interpreted as support for dynamicalejection from a dense group rather than a supernova event in a binary asa production process for runaway stars. There are, however, severalcircumstances that may adversely affect the observability of a compactcompanion, or after a supernova explosion systems may be disruptedbecause of the large natal kick velocity imparted to the neutron star asa result of asymmetries in the explosions. It is noted that there isactually evidence for both of these production routes and that they maybe expected to occur sequentially in the evolution of OB associations.
| Absolute proper motions of open clusters. I. Observational data
Mean proper motions and parallaxes of 205 open clusters were determinedfrom their member stars found in the Hipparcos Catalogue. 360 clusterswere searched for possible members, excluding nearby clusters withdistances D < 200 pc. Members were selected using ground basedinformation (photometry, radial velocity, proper motion, distance fromthe cluster centre) and information provided by Hipparcos (propermotion, parallax). Altogether 630 certain and 100 possible members werefound. A comparison of the Hipparcos parallaxes with photometricdistances of open clusters shows good agreement. The Hipparcos dataconfirm or reject the membership of several Cepheids in the studiedclusters. Tables 1 and 2 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| DO OB Runaway Stars Have Pulsar Companions?
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....111.1220P&db_key=AST
| Do OB runaways have collapsed companions ?
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974ApJ...190..653B&db_key=AST
| Etude cinematique et photometrique d'une region de Cas.
Not Available
| Catalogue d'etoiles O et B.
Not Available
| La mesure des vitesses radiales au prisme objectif. IX - 3e liste de vitesses radiales déterminées au prisme objectif à vision directe
Not Available
| Helligkeits messungen im Sternhaufen Messier 52 (NGC 7654)
Not Available
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Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Zincirli Prenses |
| Sað Açýklýk: | 23h24m33.04s |
| Yükselim: | +61°09'28.2" |
| Görünürdeki Parlaklýk: | 9.005 |
| Uzaklýk: | 236.967 parsek |
| özdevim Sað Açýklýk: | 4.9 |
| özdevim Yükselim: | -3.5 |
| B-T magnitude: | 9.145 |
| V-T magnitude: | 9.017 |
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