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A simple scale height model of the electron density in Saturn's plasma disk
Gurnett, D. A.; Persoon, A. M.; Kurth, W. S. +1 more
A study of electron densities in Saturn's inner magnetosphere is presented using measurements of the upper hybrid resonance frequency obtained from the Radio and Plasma Wave Science (RPWS) instrument on the Cassini spacecraft. The study uses data from the first 16 months of operation in orbit around Saturn. The distribution of density data spans l…
Solar Mass Ejection Imager (SMEI) observations of coronal mass ejections (CMEs) in the heliosphere
Price, S.; Simnett, G. M.; Webb, D. F. +16 more
The Solar Mass Ejection Imager (SMEI) on the Coriolis spacecraft has been obtaining white light images of nearly the full sky every 102 minutes for three years. We present statistical results of analysis of the SMEI observations of coronal mass ejections (CMEs) traveling through the inner heliosphere; 139 CMEs were observed during the first 1.5 ye…
E ring dust sources: Implications from Cassini's dust measurements
Schmidt, Jürgen; Albers, Nicole; Spahn, Frank +6 more
The Enceladus flybys of the Cassini spacecraft are changing our understanding of the origin and sustainment of Saturn's E ring. Surprisingly, beyond the widely accepted dust production caused by micrometeoroid impacts onto the atmosphereless satellites (the impactor-ejecta process), geophysical activities have been detected at the south pole of En…
Cassini UVIS observations of the Io plasma torus. III. Observations of temporal and azimuthal variability
Delamere, P. A.; Bagenal, F.; Steffl, A. J.
In this third paper in a series presenting observations by the Cassini Ultraviolet Imaging Spectrometer (UVIS) of the Io plasma torus, we show remarkable, though subtle, spatio-temporal variations in torus properties. The Io torus is found to exhibit significant, near-sinusoidal variations in ion composition as a function of azimuthal position. Th…
XMM-Newton X-ray spectroscopy of classical T Tauri stars
Schmitt, J. H. M. M.; Robrade, J.
We present results from a comparative study of XMM-Newton observations of four classical T Tauri stars (CTTS), namely
Simultaneous optical and X-ray observations of a giant flare on the ultracool dwarf LP 412-31
Liefke, C.; Schmitt, J. H. M. M.; Micela, G. +1 more
Cool stars are known to produce flares probably as a result of the magnetic reconnection in their outer atmospheres. We present simultaneous XMM-Newton optical V band and X-ray observations of the M8 dwarf LP 412-31. During the observation a giant flare occurred, with an optical amplitude of 6 mag and total energy of 3 × 1032 erg in bot…
The planetary nebula population of the Sagittarius dwarf spheroidal galaxy
Minniti, D.; Walsh, J. R.; van Hoof, P. A. M. +3 more
The identification of two new planetary nebulae (PNe) in the Sagittarius dwarf spheroidal galaxy (Sgr) is presented. This brings the total number to four. Both new PNe were previously classified as Galactic objects. The first, StWr 2-21, belongs to the main body of Sgr, from its velocity and location. The second, the halo PN BoBn1, has a location,…
Abundance Variation at the Vicinity of an Active Region and the Coronal Origin of the Slow Solar Wind
Raymond, John C.; Riley, Pete; Zurbuchen, Thomas H. +3 more
The solar wind ion composition is generally ``frozen-in'' within 5 Rsolar of the Sun. Many characteristics in the elemental abundances measured in the solar wind are believed to be set at the chromospheric and low coronal levels. By connecting plasma parameters in the coronal and in situ solar wind data, valuable insights can be obtaine…
Discovery of Outlying High-Velocity Oxygen-Rich Ejecta in Cassiopeia A
Chevalier, Roger A.; Raymond, John C.; Dopita, Michael A. +7 more
Analysis of broadband HST ACS and WFPC2 images of the young Galactic supernova remnant Cassiopeia A reveals a far larger population of outlying, high-velocity knots of ejecta with a broader range of chemical properties than previously suspected. In this paper, we concentrate on a ~=1.5 arcmin2 region located along the eastern limb of th…
Radio Measurements of the Height of Strong Coronal Magnetic Fields Above Sunspots at the Solar Limb
Brosius, Jeffrey W.; White, Stephen M.
We measure coronal magnetic field strengths of 1750 G at a height of 8000 km above a large sunspot in NOAA AR 10652 at the west solar limb on 2004 July 29 using coordinated observations with the Very Large Array, the Transition Region and Coronal Explorer, and three instruments (CDS, EIT, MDI) aboard the Solar and Heliospheric Observatory. This ob…