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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
| Observations of Clusters Using the Stromvil System. I. Standard Areas
A set of standard areas of the Stromvil system is described. Preliminaryvalues of the color indices for standard stars for photoelectric workmay be obtained from their published values in both parent (uvby andVilnius) systems. Stars in 19 open clusters already observed in bothsystems may be used as preliminary standards. Standard areas for the CCDwork are to be measured anew. For this, a set of 12 compact openclusters and globular clusters have been selected, six areas in eachhemisphere, mostly at declinations +30 deg and --30 deg. The 10--20arcmin areas will contain standard stars of 10--16 mag. They will begood for fixing the zero-point of magnitudes and color indices, for thedetermination of extinction coefficients in the Earth's atmosphere andfor the determination of color equations between instrumental CCDsystems and the standard Stromvil system. The first observations in thisprogram are planned with the new 1.8-m Vatican telescope on Mt. Graham,Arizona.
| Variable Star Detection in the Open Cluster NGC 7686
The SFASU Observatory is beginning a long term project to detect newDelta Scuti variables in open clusters. The cluster NGC 7686 wasselected as an initial test because a) star density is rather low, b) a6.4 magnitude star is well placed to be used as a guide star with theSBIG ST-4 tracker, and c) previous work of this type for this clusterexists (Peniche and Pena 1987). Standard V and R frames were obtainedover three nights using a Photometrics, Ltd. Star-1 camera attached tothe CompuScope FW-1 filter wheel on the automated 46-cm telescope. Thesedata were reduced in the usual way using Mira from Axiom Research, Inc.Results of the variable star search will be presented.
| Optical monitoring of the superluminal quasar 3C 345 in 1984-1991
This article continues a series of publications containing results of aprogram of optical monitoring of OVV quasars, blazars, and similarobjects (the Petersburg Quasar Monitoring Program), which has beenconducted at the Byurakan station of the St. Petersburg AstronomicalInstitute since 1968. Results of long-term monitoring of the quasar 3C345 in 1984-1991 are presented. The observations were conducted in the Bband and consist of 365 brightness estimates obtained on 219 nights. Theoptical variability of 3C 345 on time scales from tens of years to tensof minutes is discussed. In 1991, the appearance of a new largeamplitude slow outburst is noted (the characteristic time for brightnessvariation is of the order of a year). This outburst is similar tooutbursts in 1967-1968, 1970-1972, 1976-1977, and 1982-1983, which wereassociated with the emergence of superluminal components in themilliarcsecond radio jet of 3C 345. The 1991 outburst suggests theemergence from the core of a new superluminal component. Analysis of thefull known optical brightness curve for 3C 345 (1965-1993) shows thepossible existence of a (quasi-)period of 700 days, which implies theappearance of a new brightness maximum in the 1994 observing season.
| The Guide Star Photometric Catalog.
This paper presents data and finding charts for the Guide StarPhotometric Catalog (GSPC), which is an all-sky set of 1477pohotoelectrically determined BV sequences covering the magnitude rangefrom 9 to 15. The GSPC was created to provide photometric calibratorsfor the Guide Star Catalog, which is a catalog of approximately 2 x 10to the 7th objects needed to support the pointing of the Hubble SpaceTelescope. For declinations greater than +3 deg, the sequences generallylie near the centers of the original (Palomar Observatory-NationalGeographic Society) Sky Atlas, while for smaller declinations they lienear the centers for the ESO/SERC Southern Sky Atlas. The sequencesnominally contain (at least) six stars, each with a photometricprecision of 0.05 mag. In practice, a small number of sequences containsfewer stars, and the precisions achieved for the faintest stars are morenearly 0.1 mag.
| Seven-colour photoelectric photometry of the open cluster NGC 7686.
Not Available
| A photometric study of short period variable stars in open clusters
The photoelectric photometry of known Delta Scuti variable stars inselected open clusters (Coma, Praesepe, Pleiades, Alpha Per, and NGC2264) was carried out in order to determine the periods of pulsation.Multicolor uvby-beta photometry and a search for new variables in otheropen clusters (NGC 2539, NGC 6494, NGC 6882-5, NGC 7062, NGC 7063 andNGC 7686) were also performed.
| Catalogue of UBV Photometry and MK Spectral Types in Open Clusters (Third Edition)
Not Available
| Distribution of stars of spectral types of F7 and earlier in a field around NGC 7686.
Not Available
| Spectral Classification in Some Open Clusters.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1961ApJ...134..612S&db_key=AST
| Photometry of stars in galactic cluster fields.
Not Available
| Galactic clusters as indicators of stellar evolution and galactic structure
Not Available
| Variable stars in open clusters.
Not Available
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