Ýçindekiler
Görüntüler
Resim Yükleyin
DSS Images Other Images
Ýlgili Makaleler
10 New γ Doradus and δ Scuti Stars
We present high-resolution spectroscopy and precision photometry of fivenew γ Doradus and five new δ Scuti variables. The five newγ Doradus variables substantially increase the number of confirmedstars of this class. All 10 stars fall in the spectral class rangeF0-F2, but they are cleanly separated into two groups by theirluminosity and photometric periods. However, the period gap between theγ Doradus and δ Scuti stars is becoming very narrow since weconfirm that HD 155154 is a γ Doradus star with the shortestperiods reported to date (the shortest of its four periods is ~0.312days). We do not find any evidence in our sample for stars exhibitingboth δ Scuti- and γ Doradus-type pulsations.
| Correlated long-term light, colour and spectral variations of the Be star κ Draconis.
Intensity of the Balmer emission lines of κ Dra, documented byspectral records from the past 100 years, was found to vary with aperiod of 8406d (23.01yr). Optical brightness and continuum polarimetryseem to vary with the same period. Polarimetric changes are in phasewith the emission strength. The brightness of the object attains maximumduring the rise of emission. Then it declines to a local minimum whichcoincides with the maximum strength of the Balmer emission. Possiblequalitative interpretation of these facts is briefly outlined
| Reliable photometric reductions to the standard UBV (or uvby) system and accurate UBV magnitudes of bright standard stars from the northern part of the international Be program
A modified method of computer reduction of UBV (or uvby) photoelectricobservations to standard systems, which combines advantages of what hasso far been achieved in this area, is described in detail. A completereduction of over 46000 UBV observations obtained at Hvar Observatorybetween 1972 and 1991, and of nearly 5000 UBV observations secured atSkalnate Pleso Observatory between 1980 and 1987, was carried out usingthe new technique. It is argued that replacing the original Johnson'sUBV values for the non-variable stars that were observed by the meanvalues based on repeated observations over several years and applyingthe new reduction technique can ensure a stable reproduction of UBVmagnitudes, obviously quite close to the standard Johnson's ones, overmany years and from observatories situated at very different altitudesabove sea level within about 0.01mag in all three UBV magnitudes. A listof new accurate mean UBV values of 191 stars which were regularlyobserved at Hvar - and a part of them also at Skalnate Pleso - ascomparison, check and standard stars in the Be- and Ap-star observingprograms, is included for future use by photometric observers in theNorthern Hemisphere. For a number of these stars, we can guaranteesecular constancy within 0.mag01 during the past 5 to 15 years.
| Fifth fundamental catalogue. Part 2: The FK5 extension - new fundamental stars
The mean positions and proper motions for 3117 new fundamental starsessentially in the magnitude range about 4.5 to 9.5 are given in thisFK5 extension. Mean apparent visual magnitude is 7.2 and is on average2.5 magnitudes fainter then the basic FK5 which has a mean magnitude of4.7. (The basic FK5 gives the mean positions and proper motions for theclassical 1535 fundamental stars). The following are discussed: theobservational material, reduction of observations, star selection, andthe system for the FK5 extension. An explanation and description of thecatalog are given. The catalog of 3117 fundamental stars for the equinoxand epoch J2000.0 and B1950.0 is presented. The parallaxes and radialvelocities for 22 extension stars with large forecasting effects aregiven. Catalogs used in the compilation of the FK5 fundamental catalogare listed.
| Hyades and Sirius supercluster members brighter than magnitude (V) 7.1. II - Right ascension six to twelve hours
The present star sample is contained in the Bright Star Catalogue andits Supplement, augmented with a further supplement of 788 stars foundduring various observing programs over the past 40 years. Accurate,four-color and H-beta, or (RI), photometry is available for most of thesupercluster members. The criteria for membership are the comparisons ofthe proper motion, radial velocity, and luminosity obtained from thesupercluster parameters with the observed motions and the luminosityderived from the photometric parameters. New proper motions, based onall available catalogs, have been derived for the additional 788 starsdiscussed here, as well as all supercluster members.
| Research Note - Absolute UBV Photometry at the Zacatecas Observatory
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1985RMxAA..11...55S&db_key=AST
| UBV photometry of FK4 and FK4 supplement stars
Traditional UBV filters, together with a photomultiplier, have been usedin 40-m Cassegrain telescope observations of all northern stars of theFK4 catalog and its supplement, which have heretofore lacked V and V-Bmeasurements. The resulting UBV photometry for 320 stars is presented intabular form.
|
Yeni bir Makale Öner
Ýlgili Baðlantýlar
Yeni Bir Baðlantý Öner
sonraki gruplarýn üyesi:
|
Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Ejderha |
| Sað Açýklýk: | 12h00m52.69s |
| Yükselim: | +70°14'16.3" |
| Görünürdeki Parlaklýk: | 6.739 |
| Uzaklýk: | 90.909 parsek |
| özdevim Sað Açýklýk: | -4.2 |
| özdevim Yükselim: | 12.6 |
| B-T magnitude: | 6.868 |
| V-T magnitude: | 6.75 |
Kataloglar ve belirtme:
|
