Search Publications

Implications of Proton Anisotropy Development Observed by the ERNE Instrument During the 9 July 1996 Solar Particle Event

Laitinen, T.; Vainio, R.; Torsti, J. +1 more

We analysed the solar particle event following the 9 July 1996 solar flare. High-energy protons were detected by the ERNE instrument on board SOHO. Anisotropy of arriving protons revealed very peculiar non-monotonic development. A short period of almost isotropic distribution was imbedded into the prolonged period of beam-like distribution of 14-1…

Temperature and Velocity Diagnostics of the Red Rectangle from UV Spectra of CO and C I

Lauroesch, James T.; Sitko, Michael L.; Glinski, Robert J. +1 more

The UV spectrum of the Red Rectangle and its central source, HD 44179, was examined using the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST). Spectra have been obtained of the 0-0, 0-1, and 0-2 vibronic bands of the CO fourth positive system, the 1657 Å C I multiplet, and the 1931 Å C I line. All of the lines and b…

Redshifts of galaxies close to bright QSO lines of sight

Bowen, David V.; Blades, J. Chris; Osmer, Samantha J. +1 more

To expand the known number of low-redshift galaxies lying close to bright (V<17.2) QSO lines of sight, we have identified 24 galaxies within 11 arcmin of nine QSOs which have been observed with the Hubble Space Telescope (HST). Galaxies are found between redshifts of 0.0114 and 0.145 and lie between 39 and 749h^-1kpc from QSO sightlines. Knowin…

Structure and dynamics of the nuclear region of the spiral galaxy NGC 7217

Sil'chenko, O. K.; Zasov, A. V.

The gas velocities and brightness distribution in the inner region of NGC 7217 are analyzed. This galaxy has a regular axially symmetric shape with flocullent spiral arms that have a system of three distinct rings (outer, inner, and nuclear) - a structure that is rarely observed in the absence of a bar. Observations on the 6-m telescope of the Spe…

Optical performances of the Ultraviolet Coronagraph Spectrometer of the Solar Heliospheric Observatory

Fineschi, Silvano; Romoli, Marco; Naletto, Giampiero +6 more

Possible role of electromagnetic low frequency waves in the Io torus in the production of Jovian aurorae

Balogh, A.; Belmont, G.; Forsyth, R. J. +4 more

The possible role of ULF waves observed in the Io torus in the generation of Jovian autorae is investigated. Aaroral emissions have been observed, not only at high latitude, but also at the footprint of magnetic field lines connected to the Io torus in a limited loagitudinal range around 150°. As Ulysses passed by Jupiter, it explored the Io torus…

Overview of the soho mission

Bonnet, R. M.; Felici, F.

The SOHO spacecraft was launched on 2 December 1995, some 8 years after it started to be developed by European industry. Since 14 February 1996, SOHO is in a halo orbit around the Lagrangian point L1. It is continuously in view of the Sun, allowing uninterrupted sequences of observations of our star, a first in the development of solar physics. It…

Asymmetric Hα disk emission dominates the HST/FOS spectrum of Circinus X-1.

Caraveo, P. A.; Bignami, G. F.; Mignani, R.

CircinusX-1 is an highly variable X/radio binary source showing regular flux modulations with a periodicity of ~16.6days, probably coincident with the orbital period of the binary system. Here we present HST/FOS spectra of the optical counterpart taken around the predicted X-ray maximum. Strong Hα in emission, itself accounting for almost 50% of t…

HST Data suggest proper motion for the optical counterpart of GRB 970228.

Caraveo, P. A.; Bignami, G. F.; Mignani, R. P. +1 more

After a quarter of a century of γ-ray burst (GRB) astronomy, the Italian-Dutch satellite BeppoSAX on Feb 28^th^, 1997 detected a soft X-ray afterglow from GRB 970228 and positioned it accurately. This made possible the successful detection of an optical transient. Two public Hubble Space Telescope (HST) images of the GRB/optical transient region w…

The Infrared Spectrum of Comet Hele–Bopp as Seen by the Infrared Space Observatory

Altieri, B.; Keller, H. U.; Lellouch, E. +6 more

Spectra of comet C/1995 O1 (Hale-Bopp) were obtained with the Infrared Space Observatory (ISO) at medium resolution with the grating spectrometer in the photometer (PHT-S) and/or at high resolution with the short wavelength spectrometer (SWS) and long wavelength spectrometer (LWS) in April 1996 (Crovisier et al., 1996), September–October 1996 (Cro…