Search Publications
The changes in the UV emission lines of RR Telescopii from 1978 to 1993. I. The IUE SWP region
Hack, M.; Selvelli, P.; Zuccolo, R.
Line emission intensities and FWHMs in the range 1175-1900 Angstroms have been measured on high resolution IUE spectra of RR Tel taken from 1978 to 1993. The variations observed in the emission line intensities show a rather strong correlation with the line ionization. The decrease is of a factor larger than three and up to ten for the low-ionizat…
Wind variability in central stars of planetary nebulae. II.
Patriarchi, P.; Perinotto, M.
New high resolution IUE spectra of central stars of the planetary nebulae (CSPN) NGC 40, NGC 6543, NGC 6826, and BD +30 3639 have been obtained between August 1994 and September 1995 to explore the variability of their P Cygni profiles. The data have been analyzed together with previous observations of the same stars. Significant changes in the pr…
The FUOR characteristics of the PMS star BN Orionis inferred from new spectroscopic and photometric observations
de Winter, D.; van den Ancker, M. E.; Tjin A Djie, H. R. E. +3 more
BN Ori is a young emission-line star with a peculiar light curve. During the first half of this century the star showed strong irregular brightness- variations, similar to those of Herbig Ae stars. In the current half of the century the light curve resembles that of a FU Ori-object (FUOR, after Ambartsumian 1971). It can be characterised by an ini…
GPM1 - a catalog of absolute proper motions of stars with respect to galaxies
Rybka, S. P.; Yatsenko, A. I.
The description of the first version of the General Compiled Catalogue of Absolute Proper Motions (GPM1) for a sample of HIPPARCOS stars, derived with respect to galaxies within the plan called Catalogue of Faint Stars (KSZ, Deutch 1952), is presented. The principal aim of the GPM1 construction was to provide absolute proper motions of stars to de…
Absolute stellar proper motions with reference to galaxies of the M81 group
Meusinger, H.; Brosche, P.; Odenkirchen, M. +2 more
We report on the measurement of absolute proper motions of stars of magnitude 7 to 14.5 in a 2 deg X 2 deg field in the region of the M81 group of galaxies. This work is part of the Bonn program for the extragalactic link of Hipparcos. The proper motions were determined from a collection of photographic plates covering the time interval from 1894 …
The Potsdam contribution to the extragalactic link of the HIPPARCOS pr oper motion system
Scholz, R. -D.; Schilbach, E.; Hirte, S.
Absolute proper motions of 360 Hipparcos stars in 24 fields well distributed over the northern sky were derived from measurements of photographic plates taken mainly with the Tautenburg Schmidt telescope (134/200/400 cm). In each field (about 10 square degrees) a large number of galaxies was used to link the proper motions to the extragalactic ref…
The Bonn contribution to the extragalactic link of the HIPPARCOS proper motion system.
Tucholke, H. -J.; Brosche, P.; Odenkirchen, M.
In order to calibrate the proper motions of the Hipparcos astrometry satellite, our group has measured accurate absolute proper motions of Hipparcos stars in small fields around optically bright extragalactic radio sources or bright galaxies with star-like features. In addition, we also use fields where relative proper motions are calibrated by me…
Astrometric positions of stars with high proper motions in the Southern Hemisphere
Rousseau, J. M.; Perie, J. P.
Several stars with large proper motions, cited by W.J. Luyten, were included in the preliminary programme for the HIPPARCOS mission. When performing preparatory measurements of plates, difficulties were encountered in identifying certain of these stars when relying only on published coordinates. We have taken advantage of this work which relates t…
Interactive Deconvolution with Error Analysis (IDEA) in astronomical imaging: Application to aberrated HST images on SN 1987A, M 87 and 3C 66B
Roques, S.; Fraix-Burnet, D.; Bouyoucef, K.
The regularized reconstruction algorithm {Interactive Deconvolution with Error Analysis} (IDEA) is presented. One of its main advantages is to control the error propagation and to provide an estimation of the quality of the deconvolved image. IDEA is compared with two popular probabilistic methods: Richardson-Lucy and Maximum Entropy. These three …