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The Composite Nature of the Peculiar Star HR 6560 (HD 159870)
Wegner, Gary; Cowley, Charles R.
Ground based high dispersion photographic spectra and ultraviolet spectra obtained with the International Ultraviolet Explorer (IUE) satellite are described and employed to determine the nature of the peculiar star HR 6560 (HD 159870). Previously this object had been described as both a composite system and a strong Fm star. We inter-compare the U…
Analysis of Neckel and Chini Standard Stars in the UBVRI Photometric System
Oriol, R.
This paper studies the list of 60 faint standard stars of Neckel and Chini (1980) in theUBVRI Johnson photometric system. These standards have been used due to the collaboration in the HIPPARCOS project of our department, but this work was made in parallel of this and the results were not used. We have re-reduced the standard stars using our own m…
X-ray VS He ii λ1640 Å correlation of II Peg
Esendemir, A.; Alev, H. M.
The HeII λ1640 Å emission feature on the IUE spectra of II Peg has been compared with the observed X-ray flux. The atmospheric activity level is determined by comparing the several diagnostic line intensities with the solar case.
On the final trajectory to the solar poles
Hampel, Guenther
The Ulysses spacecraft's encounter with Jupiter is described to illustrate the swing-by maneuver from the Jovian ecliptic plane to a trajectory over the solar poles. Details are provided of the Jupiter fly-by and the theoretical principles of the swing-by maneuver including the optimization of the 70-deg dwell time and three trajectory-correction …
Deep-Space Navigation Applications of Improved Ground-Based Optical Astrometry
Null, G. W.; Owen, W. M., Jr.; Synnott, S. P.
Improvements in ground-based optical astrometry will eventually be required for navigation of interplanetary spacecraft when these spacecraft communicate at optical wavelengths. Although such spacecraft may be some years off, preliminary versions of the astrometric technology can also be used to obtain navigational improvements for the Galileo and…
Aspects of data flow for an Edison-type observatory
Penny, Alan
The design of the flow of data for an Edison-type space mission, involving a large diameter telescope for use in the near-infrared and having a mission lifetime of 10-20 yrs, is discussed. Relevant lessons on data flow that can be learned from the IUE, HST, ground-based observatories, IRAS, and SOHO are briefly considered. Future design developmen…
Ultraviolet Spectrophotometry of VV Cephei
Kang, Young Woon
The IUE archival spectra of VV Cephei were collected to investigate the eclipse nature in the ultraviolet. The temperature of the B star has been determined, as approximately 30000K, based on the flux distributions during egress. Light curves of VV Cephei were reduced from the spectrophotometry of the IUE archival spectra. Three light curves at th…
Attractive small satellite supports Ulysses measurements - URM concept for 'stereo studies' of the heliosphere
Kunow, Horst; Pailer, Norbert; Hampel, Guenter
A relatively inexpensive solution is proposed as an alternative to the withdrawn American contribution to the International Solar Polar Mission. Two alternative configurations for this Ulysses Reference Mission (URM) are briefly described.