Science Archives Publication System

A Cool Supergiant with Anomalous Behavior of the 2800 MG II Doublet

DOI: 10.1086/170430 Bibcode: 1991ApJ...378..298G

Kondo, Y.; Gurzadian, G. A.; Rustambekian, S. S. +2 more

The IUE ultraviolet spectrum for a supergiant of type G Ia, HD 135345, is obtained for the wavelength region 2000-3000 A. In the spectrum, the continuum as well as the feature of the Mg II doublet at 2800 A is found to be anomalous. The observed level of continuum increases toward short wavelengths to 2000 A, verifying that this supergiant is actu…

1991 • The Astrophysical Journal

IUE 0

Narrow Iron K-line and Warm Iron K-edge in Pulse Phase Spectra of Hercules X-1

DOI: 10.1007/BFb0031285 Bibcode: 1991LNP...385..138K

Kahabka, Peter

Spectra of the accreting neutron star Hercules X-1 observed with the EXOSAT GSPC detector on days 61,65,92 and 96 1984 were analysed for iron line features. A broad gaussian emission line with a FWHM of 1.32±0.13 keV was found during on, turn-off and short-on states in the 35-day-cycle at an energy of ~ 6.55keV in the pulse phase averaged spectra.…

1991 • Iron Line Diagnostics in X-ray Sources

Exosat 0

The reference frames in the data reduction of Hipparcos satellite.

DOI: 10.11728/cjss1991.04.308 Bibcode: 1991ChJSS..11..308L

Ling, Zhao-fen

1991 • Chinese Journal of Space Science

Hipparcos 0

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.

Bibcode: 1991AdSpR..11b....K

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).

1991 • Advances in Space Research

Hipparcos 0

Le nouvel astrolabe de l'Observatoire de Paris

DOI: 10.1007/BF00643693 Bibcode: 1991Ap&SS.177..297C

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 …

1991 • Astrophysics and Space Science

Hipparcos 0

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

DOI: 10.1086/170277 Bibcode: 1991ApJ...376..272K

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…

1991 • The Astrophysical Journal

IUE 0

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

DOI: 10.1007/BFb0031267 Bibcode: 1991LNP...385...26P

Tagliaferri, G.; Pallavicini, R.

1991 • Iron Line Diagnostics in X-ray Sources

Exosat 0

IUE Archival Spectra of 31 Cygni

Bibcode: 1991JASS....8...53K

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 ¥± …

1991 • Journal of Astronomy and Space Sciences

IUE 0

Residuals for the Observations of the 62 Selected Minor Planets

DOI: 10.1007/BF00643703 Bibcode: 1991Ap&SS.177..345C

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 …

1991 • Astrophysics and Space Science

Hipparcos 0

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

Bibcode: 1991ICRC....1..200Y

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

1991 • International Cosmic Ray Conference

COS-B 0