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A Spectroscopic Search for λ Bootis and Other Peculiar A-Type Stars in Intermediate-Age Open Clusters
As part of our continuing search for peculiar A-type stars, especiallyλ Bootis stars, in open clusters of all ages, we have obtainedclassification spectra of 130 late B, A, and early F-type stars in 12intermediate-age open clusters, including NGC 1039, 2281, 2548, 6633,7039, 7063, 7092, and 7209, IC 4665, IC 4756, Stock 2, and Praesepe. Thespectra were obtained with resolutions of 1.8 and 3.6 Å on the 0.8m telescope of Appalachian State University and were classified on theMK system. Numerous classical Ap and Am stars were found among the 130,including two new Ap stars in NGC 7092. In addition, three emission-linestars and two candidate λ Bootis stars were found. Neither ofthese λ Bootis candidates turned out to be members of theirrespective clusters. Combined with 184 stars previously classified in 10other intermediate-age open clusters, also devoid of λ Bootisstars, a statistically significant null result is obtained. We discussthe implications of this null result for our understanding of theλ Bootis mechanism.
| Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics
The Catalogue, available at the Centre de Données Stellaires deStrasbourg, consists of 13 573 records concerning the results obtainedfrom different methods for 7778 stars, reported in the literature. Thefollowing data are listed for each star: identifications, apparentmagnitude, spectral type, apparent diameter in arcsec, absolute radiusin solar units, method of determination, reference, remarks. Commentsand statistics obtained from CADARS are given. The Catalogue isavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcar?J/A+A/367/521
| Spectrophotometry of 237 Stars in 7 Open Clusters
Spectrophotometry is presented for 237 stars in 7 nearby open clusters:Hyades, Pleiades, Alpha Persei, Praesepe, Coma Berenices, IC 4665, andM39. The observations were taken by Lee McDonald and David Bursteinusing the Wampler single-channel scanner on the Crossley 0.9m telescopeat Lick Observatory from July 1973 through December 1974. Sixteenbandpasses spanning the spectral range 3500 Angstroms to 7780 Angstromswere observed for each star, with bandwidths 32Angstroms, 48 Angstromsor 64 Angstroms. Data are standardized to the Hayes-Latham system tomutual accuracy of 0.016 mag per passband. The accuracy of thespectrophotometry is assessed in three ways on a star-by-star basis.First, comparisons are made with previously published spectrophotometryfor 19 stars observed in common. Second, (B-V) colors and uvby colorsare compared for 236 stars and 221 stars, respectively. Finally,comparsions are made for 200 main sequence stars to the spectralsynthesis models of Kurucz, fixing log g = 4.0 and [Fe/H] = 0.0, andonly varying effective temperature. The accuracy of tests using uvbycolors and the Kurucz models are shown to track each other closely,yielding an accuracy estimate (1 sigma ) of 0.01 mag for the 13 colorsformed from bandpasses longward of the Balmer jump, and 0.02 mag for the3 colors formed from the three bandpasses below the Balmer jump. Incontrast, larger scatter is found relative to the previously publishedspectrophotometry of Bohm-Vitense & Johnson (16 stars in common) andGunn & Stryker (3 stars). We also show that the scatter in the fitsof the spectrophotometric colors and the uvby filter colors is areasonable way to identify the observations of which specific stars areaccurate to 1 sigma , 2 sigma , .... As such, the residuals from boththe filter color fits and the Kurucz model fits are tabulated for eachstar where it was possible to make a comparison, so users of these datacan choose stars according to the accuracy of the data that isappropriate to their needs. The very good agreement between the modelsand these data verifies the accuracy of these data, and also verifiesthe usefulness of the Kurucz models to define spectrophotometry forstars in this temperature range (>5000 K). These data define accuratespectrophotometry of bright, open cluster stars that can be used as asecondary flux calibration for CCD-based spectrophotometric surveys.
| UBV (RI)c observations of Johnson's standard sequence in IC 4665.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996MNRAS.282..313M&db_key=AST
| The medium-resolution TV spectrometer performance tests.
Not Available
| New Variable in Ophiuchus
Not Available
| The open cluster IC 4665
The results of a combined astrometric, photometric, and spectroscopicprogram to identify members of the open cluster IC 4665 are presented.Numerous new proper motion/photometric candidate members and at least 23M dwarfs with H-alpha emission have been identified. A reanalysis of IC4665 age using different methods yields conflicting results ranging fromabout 3 X 10 exp 7 yr to the age of the Pleiades. This study provides alist of candidate cluster members in the intermediate and low-massregime of this cluster. Future spectroscopic observations of thesecandidates should eventually identify true cluster members.
| Photoelectric search for CP2-stars in open clusters. V - NGC 6281, NGC 6405, IC 4665
130 stars in the medium age clusters NGC 6281, NGC 6405, and IC 4665were observed by photoelectric photometry in the Delta a-system(Maitzen, 1976) in order to detect CP2-peculiarity by the presence ofthe lambda 5200 depression feature. No CP2-star was found in IC 4665,one in NGC 6281, and 3 in NGC 6405. Star No. 77 of NGC 6405 exhibits thestrongest lambda 5200 depression ever measured by this type ofphotometry. The (very small) reddening correction of the a-values isdiscussed and found to agree well with previous papers of this series.
| Relative radial velocities from objective prism spectra in the region of nine southern open star clusters and a star field at Eta Carinae
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&AS...41..245G&db_key=AST
| Four-color and H beta photometry for open clusters.8 IC 4665.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972AJ.....77..862C&db_key=AST
| Membership of the open cluster IC 4665.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972A&A....17..193S&db_key=AST
| A photometric study of the open cluster IC 4665
Not Available
| Rotational Velocities of Stars in IC 4665
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1967ApJ...148..459A&db_key=AST
| Catalogue des étoiles mesurées dans le système photométrique de l'Observatoire de Genève
Not Available
| A photoelectric investigation of the galactic clusters IC 4665 and IC 4756
Not Available
| Positions and proper motions of stars in the region of the galactic cluster IC 4665.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1955AJ.....60..384V&db_key=AST
| The galactic cluster IC 4665.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1955AJ.....60..365H&db_key=AST
| The Standard Region Near IC 4665.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1954ApJ...119..181J&db_key=AST
| Untersuchung der offenen Sternhaufen IC 4665, NGC 6633, IC 4756
Not Available
| Relative photographic positions of 31 stars in the open cluster IC 4665
Not Available
| Photometrische Vermessung der Sternhaufen NGC 752 und IC 4665
Not Available
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Observation and Astrometry data
| Constellation: | Οφιούχος |
| Right ascension: | 17h47m21.49s |
| Declination: | +05°45'34.3" |
| Apparent magnitude: | 9.776 |
| Proper motion RA: | -1 |
| Proper motion Dec: | -10.1 |
| B-T magnitude: | 10.035 |
| V-T magnitude: | 9.798 |
Catalogs and designations:
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