Search Publications
Radio emission from Jupiter observed by ULYSSES before and after encounter
Lecacheux, A.; Barrow, C. H.
The polarization and the occurrence probability of the radio emission from Jupiter at 940 and 52 kHz are compared before and after encounter. It is found that, after encounter, the right-hand polarized Main Component of the broad-band kilometric emission (bKOM) is not present while the left-hand polarized Intermittent Component is considerably enh…
Possible in situ detection of K2+ in the Jovian magnetosphere
McNutt, Ralph L., Jr.
During the Voyager 1 and 2 encounters with Jupiter in 1979 the positive ion composition of the cold thermal plasma in the Jovian plasma sheet and cold Io torus could be obtained when the plasma Mach number in the spacecraft rest frame was sufficiently large. Clear indication of an ionic species with a mass-to-charge ratio between 16 (O+…
A BBXRT Observation of the High-Luminosity Quasar H1821+643
Yaqoob, T.; Mushotzky, R. F.; Weaver, K. A. +3 more
We present the results of an observation of the high-luminosity quasar H1821+643 with the Broad-Band X-Ray Telescope (BBXRT) performed in 1990 December. The 2-10 keV flux and power-law spectral index are found to be consistent with previous values obtained by EXOSAT and Ginga which indicates that the medium-energy continuum has remained steady for…
Recent Results from the Hubble Space Telescope
Maran, Stephen P.; Kinney, Anne L.
A selection of recent findings from the Hubble Space Telescope (HST) are presented as a supplement to the earlier review by Kinney & Maran (1991). In stellar astrophysics, noteowrthy results include the first ultraviolet science from the High Speed Photometer, as well as spectroscopic studies of black hole and neutron star binaries and a flare…
Similarity of the variability patterns in the EXOSAT and GINGA folded light curves of the Seyfert galaxy NGC 6814.
Karas, V.; Abramowicz, M. A.; Bao, G. +1 more
The Seyfert galaxy NGC 6814 is known to show periodic variation of its X-ray luminosity. We found that the sequences of peaks (variability patterns) in the folded X-ray light curves constructed from the Exosat and Ginga data are remarkably similar when one ignores amplitudes of the peaks and considers only their phases. The stable pattern consists…
ULF waves in other magnetospheres - observations and possible source mechanisms.
Khurana, K. K.
This paper presents an overview of the work done so far in the field of the ULF waves in the magnetospheres of Mercury, Jupiter, Saturn and Uranus. In the magnetosphere of Mercury, ULF waves were observed in the vicinity of the magnetopause and in the inner magnetosphere with frequencies in the range of 0.1 - 0.5 Hz. In the magnetosphere of Jupite…
IUE and HI observations of gas components towards HD 174632.
Davies, R. D.; Bates, B.; Kemp, S. N. +1 more
IUE spectra of gas components towards the nearby star HD 174632 are reported, together with 21-cm H I emission profiles obtained in the direction of the star and at several neighboring positions some 1 deg from the star. These new observations reveal a far more complex velocity structure of the interstellar gas than that reported through optical s…
Image Deconvolution of Extended Objects: A Comparison of the Inverse Fourier and the Lucy Techniques
Cunningham, C. C.; Anthony, D.
We have investigated the relative effectiveness of two deconvolution techniques in restoring spherically aberrated Hubble Space Telescope (HST) images. These images were restricted to extended objects (such as planets) of high signal-to-noise. Our reason for pursuing these studies was that one of the deconvolution methods, the Lucy iterative techn…
Hydrogen from Jupiter's atmosphere in the Jovian magnetosphere
Balsiger, H.; Geiss, J.; Galvin, A. B. +3 more
The passage of Ulysses through Jupiter's magnetosphere presents a new opportunity to investigate the contribution to the Jovian magnetosphere of ions of atmospheric origin. A determination of the magnetospheric H +/He 2+ flux ratio allows an estimate of the relative abundance of ionospheric material in the Jovian magnetospher…
The Ultraviolet Spectrum of the Planetary Nebula VY 2-2
Feibelman, Walter A.
New ultraviolet short-wavelength (SWP) IUE observations for the protoplanetary nebula Vy 2-2 were obtained in the low dispersion mode. An exposure of 400 minute duration reveals a weak stellar continuum and several definite emission lines as well as a number of absorption features. Emission features of C III], Si III], and [Ne III] are clearly obs…