Tartalom
Képek
Kép feltöltése
DSS Images Other Images
Kapcsolódó cikkek
Speckle Interferometry of New and Problem Hipparcos Binaries. II. Observations Obtained in 1998-1999 from McDonald Observatory
The Hipparcos satellite made measurements of over 9734 known doublestars, 3406 new double stars, and 11,687 unresolved but possible doublestars. The high angular resolution afforded by speckle interferometrymakes it an efficient means to confirm these systems from the ground,which were first discovered from space. Because of its coverage of adifferent region of angular separation-magnitude difference(ρ-Δm) space, speckle interferometry also holds promise toascertain the duplicity of the unresolved Hipparcos ``problem'' stars.Presented are observations of 116 new Hipparcos double stars and 469Hipparcos ``problem stars,'' as well as 238 measures of other doublestars and 246 other high-quality nondetections. Included in these areobservations of double stars listed in the Tycho-2 Catalogue andpossible grid stars for the Space Interferometry Mission.
| Speckle Interferometry of New and Problem HIPPARCOS Binaries
The ESA Hipparcos satellite made measurements of over 12,000 doublestars and discovered 3406 new systems. In addition to these, 4706entries in the Hipparcos Catalogue correspond to double star solutionsthat did not provide the classical parameters of separation and positionangle (rho,theta) but were the so-called problem stars, flagged ``G,''``O,'' ``V,'' or ``X'' (field H59 of the main catalog). An additionalsubset of 6981 entries were treated as single objects but classified byHipparcos as ``suspected nonsingle'' (flag ``S'' in field H61), thusyielding a total of 11,687 ``problem stars.'' Of the many ground-basedtechniques for the study of double stars, probably the one with thegreatest potential for exploration of these new and problem Hipparcosbinaries is speckle interferometry. Results are presented from aninspection of 848 new and problem Hipparcos binaries, using botharchival and new speckle observations obtained with the USNO and CHARAspeckle cameras.
| 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.
| The metallicity and luminosity of RV Tauri variables from medium-resolution spectra
Results are reported from spectroscopic observations of members of theRV Tauri class of pulsating variable stars at moderate resolution, andfrom photometric observations of these stars with the B and V filters ofthe Johnson UBV system and the first four filters of the Wingeight-color narrowband near-IR system. Of the 22 variables observed, TiOabsorption was detected in eight, and 10 variables displayedhydrogen-line emission at some phase. Spectral classifications wereassigned relative to the MK process. Color excesses were determined forthose variables for which spectroscopic and photometric data wereobtained within a few days of each other. The spectra obtained at aresolution of 2.5 A were fitted with synthetic spectra to determine thestellar atmospheric parameters. The range in metallicity among thevariables was found to be quite extensive, -0.3 to -0.7, and may reflecta mixture of stellar populations or masses.
| Observations of lithium dilution and rotational velocity decay in F and G giant stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975ApJ...195..649A&db_key=AST
| Narrow-band photometry of late-type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970A&AS....1..199H&db_key=AST
| MK classifications for F and G-type stars. I.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1969AJ.....74..916H&db_key=AST
|
Új cikk hozzáadása
Kapcsolódó hivatkozások
- - (nincs kapcsolódó hivatkozás) -
Új link hozzáadása
Besorolás csoportokba:
|
Pozíciós és asztrometriai adatok
| Csillagkép: | Vízöntő |
| Rektaszcenzió: | 19h09m18.41s |
| Deklináció: | +11°37'36.3" |
| Vizuális fényesség: | 7.273 |
| Távolság: | 188.324 parszek |
| RA sajátmozgás: | 5.1 |
| Dec sajátmozgás: | -17.4 |
| B-T magnitude: | 8.425 |
| V-T magnitude: | 7.369 |
Katalógusok és elnevezések:
|
INHABITED SKY
