Tartalom
Képek
Kép feltöltése
DSS Images Other Images
Kapcsolódó cikkek
A catalog of rotational and radial velocities for evolved stars
Rotational and radial velocities have been measured for about 2000evolved stars of luminosity classes IV, III, II and Ib covering thespectral region F, G and K. The survey was carried out with the CORAVELspectrometer. The precision for the radial velocities is better than0.30 km s-1, whereas for the rotational velocity measurementsthe uncertainties are typically 1.0 km s-1 for subgiants andgiants and 2.0 km s-1 for class II giants and Ib supergiants.These data will add constraints to studies of the rotational behaviourof evolved stars as well as solid informations concerning the presenceof external rotational brakes, tidal interactions in evolved binarysystems and on the link between rotation, chemical abundance and stellaractivity. In this paper we present the rotational velocity v sin i andthe mean radial velocity for the stars of luminosity classes IV, III andII. Based on observations collected at the Haute--Provence Observatory,Saint--Michel, France and at the European Southern Observatory, LaSilla, Chile. Table \ref{tab5} also available in electronic form at CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Spectropolarimetry and variability of Seyfert 1.8 and 1.9 galaxies
The phenomenon which produces the spectra classified as Seyfert 1.8 or1.9 is investigated through CCD spectropolarimetry and through analysisof three highly variable objects. The Seyfert 1.9 galaxy IRAS 1958-183has a highly polarized continuum and a broad H-alpha line which is 30percent polarized. The variability of NGC 2622, NGC 7603 (= Mrk 530),and Mrk 1018 are studied. The changes in flux of the broad lines and thecontinuum near H-alpha and H-beta are consistent with changes in theextinction in all cases. Improved IRAS photometry supports theconclusion that most Seyfert 1.8s and 1.9s are normal Seyfert 1s seenthrough a screen of dust located in or just outside of the broad-lineregions. Variability is due to changes in the optical depth of thisscreen.
| Photoelectric radial velocities, Paper XIII - 406 ninth-magnitude K0 stars in the Clube Selected Areas
Radial velocities are given for 406 ninth-magnitude late-type stars. Thestars are grouped in 10 small regions located on a systematic plan atGalactic latitudes of + or - 35 deg. Each star has been observed atleast twice, and the mean velocities are accurate to about less than 1km/s. Thirty spectroscopic binaries have been discovered; orbits havealready been given for 13 of them, and observations of the others arecontinuing.
| New UBVRI photometry for 900 supergiants
A description is presented of the results obtained in connection with asystematic program of supergiant photometry on the Johnson UBVRI system.During the eight years after the start of the program, almost 1000 starshave been observed, about 400 three or more times each. The originalselection of stars used the spectral type catalog of Jaschek et al.(1964) to choose supergiants. Since observations were possible from bothChile and Canada, no declination limits were imposed, and no particularselection criteria were imposed other than to eliminate carbon stars.These are so red as to require enormous extrapolations of thetransformation equations.
| Accuracy of two-dimensional spectral classes derived through DDO photometry.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977AJ.....82..832Y&db_key=AST
|
Új cikk hozzáadása
Kapcsolódó hivatkozások
- - (nincs kapcsolódó hivatkozás) -
Új link hozzáadása
Besorolás csoportokba:
|
Pozíciós és asztrometriai adatok
| Csillagkép: | Herkules |
| Rektaszcenzió: | 16h54m05.45s |
| Deklináció: | +27°35'27.8" |
| Vizuális fényesség: | 8.003 |
| Távolság: | 253.165 parszek |
| RA sajátmozgás: | 2 |
| Dec sajátmozgás: | 7.7 |
| B-T magnitude: | 9.276 |
| V-T magnitude: | 8.109 |
Katalógusok és elnevezések:
|
