Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
|
Effective temperature scale and bolometric corrections from 2MASS photometry
We present a method to determine effective temperatures, angularsemi-diameters and bolometric corrections for population I and II FGKtype stars based on V and 2MASS IR photometry. Accurate calibration isaccomplished by using a sample of solar analogues, whose averagetemperature is assumed to be equal to the solar effective temperature of5777 K. By taking into account all possible sources of error we estimateassociated uncertainties to better than 1% in effective temperature andin the range 1.0-2.5% in angular semi-diameter for unreddened stars.Comparison of our new temperatures with other determinations extractedfrom the literature indicates, in general, remarkably good agreement.These results suggest that the effective temperaure scale of FGK starsis currently established with an accuracy better than 0.5%-1%. Theapplication of the method to a sample of 10 999 dwarfs in the Hipparcoscatalogue allows us to define temperature and bolometric correction (Kband) calibrations as a function of (V-K), [m/H] and log g. Bolometriccorrections in the V and K bands as a function of T_eff, [m/H] and log gare also given. We provide effective temperatures, angularsemi-diameters, radii and bolometric corrections in the V and K bandsfor the 10 999 FGK stars in our sample with the correspondinguncertainties.
|
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
|
The nature of some doubtful open clusters as revealed by HIPPARCOS
We discuss the nature of some galactic open clusters by using propermotions and parallaxes from the Hipparcos and ACT catalogues. We showthat the clusters Collinder 399, Upgren 1, NGC 1252 and Melotte 227 donot exist. Collinder 132 is found to be mainly composed out of membersof an OB association, but there may be a star cluster present in thisarea too. Roeser & Bastian (1994) proposed that NGC 2451 consists oftwo star clusters. We show that NGC 2451 A definitively does exist, NGC2451 B may exist. A star cluster may also be present in the area ofRoslund 5. The Hipparcos data finally confirm the reality of Collinder135.
|
Correlation of the HIPPARCOS and Allegheny Observatory Parallax Catalogs
No significant difference is found between the systems of the Hipparcosand Allegheny Observatory MAP parallax catalogs. The correlation of theparallaxes of 63 stars common to both programs is 0.9995 +/- 0.0001,with an average standard deviation of the difference of 0.0023". Whilethere is no indication of systematic difference in the two programs, ourstudy suggests that the formal errors in one or both catalogs aresomewhat underestimated.
|
The membership of Upgren One
Upgren One is a group of seven F stars which has been proposed as theremnant of a nearby old open duster. We have monitored the radialvelocities of these stars with the CfA digital speedometers. Two of thestars have velocities which are clearly inconsistent with physicalassociation with the other five stars. Those five include a long-periodbinary and an unusual triple system. The velocity dispersion of the fivestars is too large to be bound under reasonable assumptions about thetotal mass.
|
Photometry of astrometric reference stars
UBVRI, DDO, and uvby, H-beta photometry of astrometric reference starsis presented. Spectral types and luminosity classifications made fromthe colors are used to determine their spectroscopic parallaxes. In thispaper, colors for 309 stars in 25 regions are given, and classificationsfor 210 stars have been made. These stars form reference frames in theAllegheny Observatory Multichannel Astrometric Photometer astrometricprogram, and in the Praesepe cluster reduced by Russell (1976). It isfound that the present photometric spectral types are reliable to within2.5 spectral subclasses.
|
Seven colour photoelectric photometry of the open cluster an (Upgren).
Not Available
|
A study of Upgren 1
Upgren and Rubin (1965) have suggested that a small group of bright Fstars, in the direction of the galactic north pole, may be the remnantof an old cluster. The multichannel astrometric photometer (MAP) hasbeen used to determine the parallaxes of six of the candidate stars withan average precision of 1.1 thousandths of an arcsecond (1.1 mas). Thederived distances are, as suggested, similar, and an unusual spacedensity of F stars seems indicated. However, the derived spacevelocities indicate that the proposed cluster is composed of members oftwo dynamically different groups.
|
Spectrophotometry of the F-Stars Members of the UPGREN-1 Group
Not Available
|
UPGREN1 - an Old Cluster Near the End of its Life
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1982PASP...94..229U&db_key=AST
|
Further Studies of A-Stars and F-Stars in the Region of the North Galactic Pole - Part Three - a Catalogue of Star Names and Positions
Not Available
|
Proper motions of several tightly grouped F stars
In a recent paper Upgren and Rubin (1965) suggested that a tight groupof F stars near the north galactic pole may form a small relatively oldgalactic cluster. The proper motions of these stars are examined indetail, and it is concluded that it is unlikely that the stars form asingle physical group.
|
An Old Open Cluster Near the North Galactic Pole
Not Available
|
Space distribution of stars of intermediate spectral type in a North galactic pole region.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1963AJ.....68..194U&db_key=AST
|
Investigations on the stars in high galactic latitudes. III. Spectrophotometric analysis of about 3000 stars down to the photographic magnitude 13.5.
Not Available
|
