Ýçindekiler
Görüntüler
Resim Yükleyin
DSS Images Other Images
Ýlgili Makaleler
Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
| BVR photometry of a newly identified RS CVn binary star HD 61396
BVR photometry of a recently identified RS CVn binary star HD 61396,carried out during 2001, is presented. The new photometry revealsignificant evolution in the shape and amplitude of light curve whencompared with those reported earlier by Parihar et al. [MNRAS 314 (2000)733]. The traditional two-starspot model has been used to obtain thespot parameters from the observed light curve. Changes in the spot areaand their location on the stellar surface are discernible from theextracted parameters from the new photometry.
| Optical, X-ray and radio observations of HD 61396: a probable new RS CVn-type binary
We have carried out BVR photometric and Hα spectroscopicobservations of the star HD 61396 during 1998 March 20 to 1999 April 3.We have discovered regular optical photometric variability from thisstar, with an inferred period of 31.95+/-0.10d, and an amplitude of~0.18mag. A possible period of 35.34+/-0.12d, as determined withHipparcos, cannot be completely ruled out, however. Modelling of itsphotometric light curve with two circular spots indicates that 5-21 percent of the stellar surface is covered by dark starspots which are ~830Kcooler than the surrounding photosphere, and produce the observedrotational modulation of the optical flux. Optical spectroscopy revealsa variable Hα emission feature, indicating that it is an unusuallyactive star. In addition, we have analysed archival X-ray data of HD61396, obtained from serendipitous observations with the ROSAT X-rayobservatory, and we also discuss the radio properties of this star,based on both published Green Bank and unpublished VLA observations. Thestrong photometric variability and Hα emission, the relativelyhard X-ray spectrum, and the high X-ray and radio luminosities implythat HD 61396 is most likely to be a member of the RS CVn class ofevolved active binary stars. Its X-ray and radio luminosities place itamong the five most luminous active binaries detected so far.
| 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.
|
Yeni bir Makale Öner
Ýlgili Baðlantýlar
Yeni Bir Baðlantý Öner
sonraki gruplarýn üyesi:
|
Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Zurafa |
| Sað Açýklýk: | 07h37m32.45s |
| Yükselim: | +60°32'19.0" |
| Görünürdeki Parlaklýk: | 6.991 |
| Uzaklýk: | 125.313 parsek |
| özdevim Sað Açýklýk: | -2.1 |
| özdevim Yükselim: | 4.9 |
| B-T magnitude: | 7.058 |
| V-T magnitude: | 6.997 |
Kataloglar ve belirtme:
|
