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Infrared Properties of a Large Ring Around the LBV G79.29+0.46

Landecker, T. L.; Heske, A.; Wendker, H. J. +2 more

G79.29+0.46 seems to be an unique object. Discovered as a nearly perfect ring in the radio continuum all subsequent observations are consistent with the interpretation that it is a large ring nebula (4‧) around an heavily reddened LBV. Our ISOPHOT and LWS observations on board of ISO show that an infrared ring coincides with the radio ring. Line e…

The Cassini-Huygens SSP refractometer : ref

Geake, J. E.; Mill, C. S.

The refractometer (REF) in the Huygens probe Surface Science Package (SSP) is a linear critical-angle refractometer ; it covers the refractive index range 1.2500-1.4500 with a discrimination of 0.0005, giving an accuracy of about 0.5% in the relative abundance of methane and ethane in the expected mixture on the possibly liquid surface of Titan. L…

On the diamagnetic effect associated with the ion pile-up region in the coma of comet Halley

Neubauer, F. M.; Israelevich, P. L.; Ershkovich, A. I.

The ion pile-up region in the comet Halley ionosphere observed on the inbound leg of the Giotto trajectory is accompanied by a decrease of the magnetic field strength. This magnetic field dip is explained by means of a diamagnetic effect of the plasma density increase in the pile-up region. Maximum of the plasma pressure seems to coincide with the…

Accuracy of Plasma Moment Derivatives

Vogt, Joachim; Paschmann, Götz

Solar Wind

Marsch, Eckart

A concise tutorial review is given of solar wind observations and theory with emphasis on the more recent findings from the Ulysses and SOHO missions, in particular about the plasma state and structure of the polar coronal holes, and on theoretical efforts to model the coronal hole flows and the fast solar wind emanating therefrom. The structure o…

Hubble Space Telescope Spectra of 3C 279: A Lyman Limit System at Low Redshift

Stocke, John T.; Blades, J. Chris; Penton, Steve +2 more

We present Hubble Space Telescope (HST) Faint Object Spectrograph spectra of the blazar 3C 279 obtained during two recent optical outbursts of this source, maximizing the sensitivity to weak foreground absorption systems at far-UV wavelengths for this sight line. Eighteen absorption systems were detected above an observed 3 sigma limiting equivale…

Extreme-ultraviolet diagnostics of pick-up ions in regions close to the solar corona. I. Feasibility of new observations

Fichtner, Horst; Fahr, Hans-Joerg; Scherer, Horst

Recent investigations of pick-up ion data obtained with the AMPTE and the Ulysses spacecraft resulted in the discovery that, in contrast to previous expectation, pick-up ion velocity distribution can be anisotropic. Such anisotropy results from a smaller efficiency of pitch-angle scattering than usually assumed and translates into a larger scatter…

ISO LWS Observations of H2O from R Cas: A Consistent Model For Its Circumstellar Envelope

Omont, A.; Barlow, M. J.; Cox, P. +6 more

We present an ISO LWS 43-197 µm grating spectrum of the oxygen-rich AGB star R Cas. The spectrum is rich of isolated and blended H2O lines. For their identification and in order to determine the physical parameters of the circumstellar envelope, we have constructed a model which treats radiative transfer, chemical exchange and photodissociation re…

Measurement of Plasma Velocity Distributions

Schwartz, Steven J.; Fazakerley, Andrew N.; Paschmann, Götz

The 3.4 Microns Absorption Feature in CRL 618

Tielens, A. G. G. M.; Geballe, T. R.; Chiar, J. +1 more