Search Publications

The reference frames in the data reduction of Hipparcos satellite.

Ling, Zhao-fen

Infrared and radio astronomy, and astrometry. Proceedings. Symposia 7, 8 and Topical Meeting of the COSPAR Interdisciplinary Scientific Commission E (Meeting E5) of the COSPAR 28. Plenary Meeting: Infrared and radio astronomy, and astrometry, The Hague (Netherlands), 25 Jun - 6 Jul 1990.

Perryman, M. A. C.; Smoot, G. F.; Wesselius, P. R. +2 more

Contents: 1. Astrometry from space (Symposium 7). 2. The infrared and submillimeter universe at high redshift (Symposium 8). 3. Space VLBI (Meeting E5).

Le nouvel astrolabe de l'Observatoire de Paris

Chollet, F.

The new polyvalent astrolabe of the Paris Observatory is described. After some optical modifications this new instrument is able to observe the stars, some planets, and the sun with an internal error less than 0.4 arcsec in the last case. Some new modifications are in progress to obtain better results and stability in the solar observations. This …

Ultraviolet Variability of the Massive W-R Binary System HDE 311884 = WR 47

Moffat, Anthony F. J.; Koenigsberger, Gloria; Auer, Lawrence H.

IUE observations and their analysis of the massive WN6 + O binary system HDE 311884 are presented. The phase-dependent variations are like those of WN4-6 binaries studied previously, with atmospheric eclipses evident in the N IV 1718 A and C IV 1550 A lines, and in the Fe V + VI pseudocontinuum at wavelengths below 1480 A. The considerable variabi…

Low-Resolution Spectra of Stellar Coronae and Flares with EXOSAT: The Iron K-line

Tagliaferri, G.; Pallavicini, R.

IUE Archival Spectra of 31 Cygni

Kang, Young Woon

UV light curve of 31 Cygni has been made from the IUE high dispersion spectra. The depth of primary minimum of the light curve is 5.2 magnitudes because the B4 star's steep spectral gradient. The light curve has been analyzed by the method of Wilson and Devinney Differential Correction(WD). The radial velocities have been measured using the Mg ¥± …

Residuals for the Observations of the 62 Selected Minor Planets

Calaf, J.

This paper reports results of the improvement of orbital elements of the 62 minor planets included in the Hipparcos mission. The astrometric observations supplied by the Minor Planet Center and the meridian circles at La Palma and Bordeaux observatories were used by the author. The accuracy reached (RMS O-C) for each minor planet and for La Palma …

Reexamination of discrete sources with ????b > 20 from COS-B data

Ma, Y.; Luo, Y.; Yu, K. N. +1 more

Using the cross-correlation and bootstrap sampling methods, the COS-B data in the observations with I b I > 20° are re-examined to search for discrete sources. Two source features have been identified and the possible counterparts are the pulsar PSR0950+08 and the weak

Hipparcos: First results of the photometric processing

Mignard, F.; Grenon, M.; Falin, J. L. +1 more

The analysis of the photon counts collected by the ESA HIPPARCOS satellite allows to determine for each program star a magnitude in the H-filter. We present the general principles of the data reduction restricted to the photometry. It is shown that photometric recognition of close binary stars, down to 100 arcsec separation is an attainable goal, …

Strong Absorption Lines in the Spectrum of Supernova 1987A in the First Months after the Explosion - Variations of Lines of Heavy Elements

Lyubimkov, L. S.