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The IUE Absorption Spectrum of the Nucleus of NGC 246: Mostly C IV and O VI
Feibelman, Walter A.
We present a list of more than 140 absorption features and their equivalent widths for the central star of the planetary nebula NGC 246 as observed in the wavelength range lambda-1169-lambda 2000. High signal-to-noise ratios are achieved by coadding nine high-dispersion SWP spectra, representing a total of nearly 22 hrs observing time. The IUE spe…
Alfvenic Fluctuations in the Solar Wind: A Case Study Using ULYSSES Measurements
Balogh, A.; Forsyth, R. J.; Scime, E. E. +3 more
We present preliminary results of a study of solar wind Alfvénic fluctuations using magnetometer and plasma measurements from the spacecraft Ulysses. We focus on a particular case study, and use ‘wave language’ to discuss the fluctuations. The observations are consistent with a mixture of convected structures and Alfvén wave trains. Furthermore, o…
Goddard High-Resolution Spectrograph Observations of the Interacting Binary System W Serpentis
Rosenblatt, E. I.; Shore, S. N.; Weiland, J. L. +2 more
Spectroscopic observations of the interacting binary system W Serpentis have been made at two orbital phases using the Goddard High-Resolution Spectrograph (GHRS) aboard the Hubble Space Telescope (HST). Differences in Si IV t393, 1403λλ emission-line strengths and profile shapes observed between the two phases suggest that a hot spot exists where…
Interstellar Lines in HD 72127A and B: A Binary Star behind the VELA Supernova Remnant
Jenkins, Edward B.; Wallerstein, George; Vanture, Andrew
Spectra with a resolution of 20,000 obtained with the Goddard High Resolution Spectrograph on board Hubble Space Telescope show substantial differences in the interstellar absorption features for two stars, HD 72127A and B, despite their small separation of 4'S. Some of the material that produces these features is associated with shocked clouds in…
Hubble Space Telescope astrometric observations of pre-main sequence stars from the HIPPARCOS Program. II.
Lattanzi, M. G.; Bucciarelli, B.; Bernacca, P. L. +2 more
We report on high angular resolution observations with Fine Guidance Sensor (FGS) No. 3 aboard the Hubble Space Telescope of five low-mass pre-main sequence stars (T Tauri stars), which have also been observed with the Hipparcos satellite. We have observed BP Tau, RU Lup, RY Lup, AK Sco, and DI Cep and have found that none of them have companions …
Energetic Particles at High Latitudes
Wibberenz, G.; Müller-Mellin, R.
We review work on diffusion coefficients of energetic particles with an attempt to extract implications on their behaviour at high latitudes. In the ecliptic plane results from solar energetic particle propagation between the Sun and about 5 AU can be described by an effective radial mean free path λ r which is approximately constant a…
IMF Connection for Energetic Protons Observed at ULYSSES via Mid-Latitude Solar Wind Rarefaction Regions
Simnett, G. M.; Armstrong, T. P.; Roelof, E. C.
As Ulysses moved inward and southward from mid-1992 to early 1994 we noticed the occasional occurrence of “inter-events”, lasting about 10 days and falling between the recurrent events, observed at proton energies of 0.48 97 MeV, associated with Corotating Interaction Regions (CIR). These inter-events were present for several sequences of two or m…
High Energy Cosmic Ray Nuclei Results on Ulysses: 1. Mission Overview
Sierks, H.; Kunow, H.; Wibberenz, G. +9 more
The cosmic ray flux observed with the Kiel Electron Telescope on board the ULYSSES spaceprobe varies with solar activity as well as with heliospheric position. Determination of the latitudinal gradients requires a careful analysis of the influences of the current sheet tilt angle, the number of major solar flares, interplanetary shocks and interac…
Circumstellar Absorption and Emission in the Post-AGB Stars HR4049 and HD213985
Waters, L. B. F. M.; Van Winckel, H.; Waelkens, C. +1 more
The evolved C-rich low-mass stars HR 4049 and HD 213985 present variable circumstellar extinction and emission. Observations of HR 4049 strengthen the link between the far-UV extinction rise and the presence of small C-rich particles. Variability of the UV absorption bump in HD 213985 is reported here for the first time and is discussed.
Detection of an X-ray flare on the low-activity G 8 III-type giant β Boo.
Reimers, D.; Huensch, M.
We present ROSAT observations of an X-ray flare on the G8III-type giant β Boo, which seems to be the first known flare on a single, low-activity, late-type giant. The flare occured on 8 August 1993. The PSPC count rate increased within ~5 minutes nearly by a factor of 10. Most of the decay phase could be traced, before the observation interval end…