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Time-Series Ensemble Photometry and the Search for Variable Stars in the Open Cluster M11
This work presents the first large-scale photometric variability surveyof the intermediate-age (~200 Myr) open cluster M11. Thirteen nights ofdata over two observing seasons were analyzed (using crowded field andensemble photometry techniques) to obtain high relative precisionphotometry. In this study we focus on the detection of candidate membervariable stars for follow-up studies. A total of 39 variable stars weredetected and can be categorized as follows: one irregular (probablypulsating) variable, six δ Scuti variables, 14 detached eclipsingbinary systems, 17 W UMa variables, and one unidentified/candidatevariable. While previous proper-motion studies allow for clustermembership determination for the brightest stars, we find thatmembership determination is significantly hampered below V=15, R=15.5 bythe large population of field stars overlapping the cluster mainsequence. Of the brightest detected variables that have a highlikelihood of cluster membership, we find five systems in which furtherwork could help constrain theoretical stellar models, including onepotential W UMa member of this young cluster.
| The Identification of New Be Stars in GAUDI
The Ground-based Asteroseismology Uniform Database Interface (GAUDI) isthe result of the preparatory work performed for the COROT satellite. Inthe data available in GAUDI we discovered 17 B-type stars that showemission in their Balmer lines and were not known to display suchemission before, including at least 16 nonsupergiant ones. We thusreclassify those stars as Be stars. These 17 new Be stars increase thenumber of Be stars in the field of view of COROT by ~25%, which isimportant for the target selection of the mission. Moreover, ~70% of thediscovered Be stars are of late subtypes. Be stars have been mostlyfound among early subtypes until now, but this could be due to anobservational bias. Finally, one of the discovered stars is either aslowly rotating shell Be star or a Herbig Be star with a low vsini,which makes this star especially interesting.Based on GAUDI, the data archive and access system of the ground-basedasteroseismology programme of the COROT mission. The GAUDI system ismaintained at LAEFF (http://ines.laeff.esa.es/corot/). LAEFF is part ofthe Space Science Division of INTA.
| 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.
| Meridian observations made with the Carlsberg Automatic Meridian Circle at Brorfelde (Copenhagen University Observatory) 1981-1982
The 7-inch transit circle instrument with which the present position andmagnitude catalog for 1577 stars with visual magnitudes greater than11.0 was obtained had been equipped with a photoelectric moving slitmicrometer and a minicomputer to control the entire observationalprocess. Positions are reduced relative to the FK4 system for each nightover the whole meridian rather than the usual narrow zones. Thepositions of the FK4 stars used in the least squares solution are alsogiven in the catalog.
| M11 - A study of its inner and outer regions
Two hundred and seventy-five new photographic V and B magnitudes basedon the membership study of M11 by McNamara et al. (1977) are combinedwith earlier determined magnitudes by Johnson et al. (1956). Theresulting color-magnitude diagram of M11 is one of the most complete yetproduced for a galactic cluster. The cluster age and distance aredetermined to be about 200,000,000 yr and 1900 pc. The extensive halosurrounding this cluster, reported by McNamara and Sanders (1977), isconfirmed and interesting differences between the CM diagrams of theinner and outer regions are discussed.
| The galactic cluster M11
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1956ApJ...124...81J&db_key=AST
| Ausmessungen der vier offenen Sternhaufen NGC 7789, Messier II und 35, NGC 6939
Not Available
| Spectrophotometric methods for determining stellar luminosity.
Not Available
| Studies based on the colors and magnitudes in stellar clusters. IV.
Not Available
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| Сазвежђа: | Штит |
| Ректацензија: | 18h51m07.98s |
| Deклинација: | -06°16'45.0" |
| Apparent магнитуда: | 8.566 |
| Даљина: | 10000000 parsecs |
| Proper motion RA: | -0.3 |
| Proper motion Dec: | -0.1 |
| B-T magnitude: | 9.156 |
| V-T magnitude: | 8.615 |
Каталог и designations:
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