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Relation between Stellar Evolution and Circumstellar Processes

Maeder, André

ISOPHOT Observations of Early-type Stars

Leitherer, C.; Owocki, S. P.; Blomme, R. +4 more

Transonic Decretion Discs Around be Stars

Okazaki, A. T.

Stellar uvbybeta photometry in three EUV shadow directions

Knude, J.

We present the uvbybeta data used to locate the dust and derive distances for nearby diffuse interstellar clouds in the EUV shadows lb27-31, lb165-32 and lb329+46 discovered by the Extreme Ultraviolet Explorer. The photometrically derived parallaxes of our program stars are compared to the parallaxes listed in the Hipparcos Catalog. Within the pho…

Fast and Accurate Inflight Calculations of Electron Space Plasma Parameters

Fazakerley, A. N.; Carter, P. J.; Gowen, R. A. +2 more

Satellite and rocket borne experiments impose unique requirements on the systems that control them. High input data rates from sensors have to be coupled to a limited spacecraft telemetry resource. A suite of algorithms designed to ensure the most effective possible use of the telemetry allocation for an instrument studying space plasma electrons …

Cassini Huygens mission : the exploration of the Saturn system. Radio science experiments : Radio Frequency Instrument Subsystem

Perrot, Bruno; Giordani, Roberto

Many of the Cassini radio science experiments will require very stable microwave signals from the ground station that are transponded phase coherently on board the spacecraft. The Radio Frequency Instrument Subsystem is designed to provide this latter capability with high performance downlink signals at S-band and Ka-band. The signal level and pha…

White clouds on Io?

Rogers, J. H.

This paper reports rapid changes in the distribution of bright white patches in one region of Io, close to the subjovian point and the caldera Karei Patera. A stable pattern of white patches in this region was recorded by Voyager in 1979. A strikingly different pattern was shown in the first Galileo-G1 image (1996 June). However, the patterns in a…

ISO-SWS Observations of Stars with Unusual IRAS LRS Characteristics

Deguchi, S.; Mizutani, M.; Yamamura, Y.

Observations of 5 stellar sources with unusual characteristics of IRAS Low Resolution Spectra were made with the SWS on ISO. Observed stars are 4 late-type stars with silicate bands and one planetary nebula. Their IRAS LRS contain somewhat unusual features in respect of the 10/18 µm intensity ratio or narrow emission feature from unknown molecular…

HST Observations of Carbon and Hydrogen in DB White Dwarfs

Provencal, J. L.; Shipman, H. L.

The differences in the structure of DA and DB white dwarfs hinge on the asteroseismological analysis of GD 358. However, spectroscopic investigation of this important white dwarf found spectral peculiarities, notably a very low hydrogen abundance and the presence of carbon. These results initiated further investigation of chemical composition of D…

Absorption Features of Ices Toward NGC7538 IRS1

Leto, G.; Strazzulla, G.; Nisini, B. +2 more

In this paper we present a comparison of the observed absorption band at about 660 cm-1 (15.1 µm) toward NGC7538 IRS1 attributed to the bending mode of solid CO2 with laboratory spectra of ion irradiated mixtures.