Ýçindekiler
Görüntüler
Resim Yükleyin
DSS Images Other Images
Ýlgili Makaleler
Mesures de vitesses radiales. VIII. Accompagnement AU sol DU programme d'observation DU satellite HIPPARCOS
We publish 1879 radial velocities of stars distributed in 105 fields of4^{\circ} \times 4^{\circ}. We continue the PPO series \cite[(Fehrenbachet al. 1987;]{Feh87} \cite[Duflot et al. 1990, 1992 and 1995),]{Du90}using the Fehrenbach objective prism method. Table 1 only available inelectronic form at CDS via to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Absolute stellar proper motions with reference to galaxies of the M81 group
We report on the measurement of absolute proper motions of stars ofmagnitude 7 to 14.5 in a 2 deg X 2 deg field in the region of the M81group of galaxies. This work is part of the Bonn program for theextragalactic link of Hipparcos. The proper motions were determined froma collection of photographic plates covering the time interval from 1894to 1994. The absolute reference system for the proper motions isrepresented by the galaxies M81, M81, and NGC3077, for which accurateoptical reference positions were obtained by means of an imagecross-correlation technique. For the majority of stars, the internalproper motion accuracy is better than 1 mas/a. The precision of therealization of the absolute system is found to be around 1 mas/a. Intotal, our measurements yield absolute proper motions for 24 Hipparcosstars and positions, proper motions and photometry for 330 additionalstars including a number of visual binaries and high proper motionstars. Among the latter one G-type sub-dwarf is identified. The resultsare relevant as a contribution to the Hipparcos link, but also as adatabase for kinematic investigations.
| Interstellar and intergalactic gas towards SN 1993J in M 81: A study of optical and 21 CM spectra
We present a study of the interstellar and intergalactic clouds locatedin the direction of the recent supernova 1993J in M81 based on theanalysis of optical and 21 cm spectra obtained during the first nightsafter its discovery. The optical spectra were taken at high spectralresolution (FWHM 4 to 6 km/s) using the 4.2 m William Herschel Telescope(La Palma, Spain), covering the resonance lines of CN, Ca II, Ca I,CH(+), CH, Na I, Li I and K I. We also observed in Ca II a sample offoreground Galactic stars in the field of the supernova. The 21 cmspectra were taken with the 100 m Effelsberg Radiotelescope (beam FWHMapproximately equals 9 min) at the position of SN 1993J and in 6positions around the supernova, at 10 min separation.
| Photometric and spectroscopic analysis of high galactic latitude molecular clouds. II - High-resolution spectroscopic observations of NA I, CA II, CA I, CH, and CH(+1)
High-resolution spectroscopic observations in the wavelengths of thespecies Na I, Ca II, and Ca I and the molecular species CH and CH(+)have been performed toward stars behind a variety of high galacticlatitude molecular clouds (HLCs). Seventeen new detections of molecularabsorption are reported. The sizes, densities, and molecular contentfound for the HLCs are consistent with an interpretation of HLCmolecular cores as extremely compact structures of enhanced molecularcontent which may have evolved from larger H I shells.
| Four-colour and H-beta photometry of blue stars selected from a balloon-ultraviolet survey and other sources
New uvby and/or H-beta photometry is obtained at the Chiranhigh-altitude outstation for 105 stars. Certain of the program stars areselected from a comparison of the SCAP 2000 balloon-ultraviolet skysurvey of the Laboratoire d'Astronomie Spatiale with the correspondingblue and red prints of the Palomar Observatory sky survey. Only a smallportion of these stars turn out to be B stars, whereas, the rest of thestars, which are selected from a variety of other sources, are mostly Bstars and if of normal luminosity are in many cases many Population Iscale heights from the galactic plane. It is shown that theidentification of B stars is practicable only at a good observing siteand that if H-beta photometry is also obtained, sdOB, sdB, and hothorizontal branch B stars can be distinguished from normal stars bytheir position in the beta/c(0) diagram.
|
Yeni bir Makale Öner
Ýlgili Baðlantýlar
Yeni Bir Baðlantý Öner
sonraki gruplarýn üyesi:
|
Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Buyuk Ayi |
| Sað Açýklýk: | 10h05m00.19s |
| Yükselim: | +70°13'45.2" |
| Görünürdeki Parlaklýk: | 8.561 |
| Uzaklýk: | 217.865 parsek |
| özdevim Sað Açýklýk: | 9.7 |
| özdevim Yükselim: | 4.1 |
| B-T magnitude: | 8.761 |
| V-T magnitude: | 8.578 |
Kataloglar ve belirtme:
|
