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
|
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.
|
Physical parameters of multiple systems like the Trapezium of early spectral types, derived from uvby-beta photometry. II.
Not Available
|
Physical parameters of multiple systems like the Trapezium of early spectral types, derived from uvby-beta photometry. I.
Not Available
|
Uvby-Beta Photometry of the Components of the Trapezium-Type Multiple Systems
Not Available
|
Galactic OB associations in the northern Milky Way Galaxy. I - Longitudes 55 deg to 150 deg
The literature on all OB associations was reviewed, and their IRAS pointsource content was studied, between galactic longitude 55 and 150 deg.Only one third of the 24 associations listed by Ruprecht et al. (1981)have been the subject of individual studies designed to identify thebrightest stars. Distances to all of these were recomputed using themethod of cluster fitting of the B main sequence stars, which makes itpoossible to reexamine the absolute magnitude calibration of the Ostars, as well as for the red supergiant candidate stars. Also examinedwas the composite HR diagram for these associations. Associations withthe best defined main sequences, which also tend to contain very youngclusters, referred to here as OB clusters, have extremely few evolved Band A or red supergiants. Associations with poorly defined mainsequences and few OB clusters have many more evolved stars. They alsoshow an effect in the upper HR diagram referred to as a ledge byFitzpatrick and Garmany (1990) in similar data for the Large MagellanicCloud. It is suggested that the differences in the associations are notjust observational selection effects but represent real differences inage and formation history.
|
Photometry of the young open cluster Trumpler 37
Photoelectric UBV observations of 120 stars in the young open clusterTrumpler 37 are presented, primarily in the magnitude range 10.0 - 13.5.An analysis of the color-magnitude diagram of the cluster yields an ageof 6.7 million yr and reveals the presence of a number of possiblepre-main-sequence stars in the cluster.
|
Trapezium-type multiple systems
Trapezia are detected among multiple stars with primaries of O and Bspectral types. Data from Salukvadze (1979) displaying the relationshipbetween Trapezium-type systems and associations and galactic clustersare presented. The kinematics of 15 Trapezium-type multiple systems withprimaries of O-B2 spectral classes is examined. It is observed that 14of the 15 Trapezia studied showed expansion and an example of thiseffect is provided.
|
Trapezium-type multiple systems
The non-stable nature of stellar motions in Trapezium-type multiplesystems is discussed. The disintegration time of such systems is severalorders of magnitude less than the life-time of their components, andconsiderably less than the disintegration time of stellar associations.The importance of ground-based and orbital observations ofTrapezium-type systems is stressed.
|
Kinematics of multiple Trapezium type systems
The kinematics of selected multiple Trapezium type systems is studied onthe basis of currently available observational data, includingphotographic records. Among the 15 systems studied, 14 exhibitexpansion. Of these, 11 have an overall expansion, while three have onecomponent far from the primary component.
|
The work with astronomical data catalogues for compilation of Abastumani catalogue of Trapezium type multiple systems and their investigation.
Not Available
|
Photometric Study of Trapezium-Type Systems
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1979RMxAA...4..287E&db_key=AST
|
Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978ApJS...38..309H&db_key=AST
|
INHABITED SKY
