Search Publications
Auroral footprint of Ganymede
Gérard, Jean-Claude; Clarke, John T.; Grodent, Denis +4 more
The interaction of Ganymede with Jupiter's fast rotating magnetospheric plasma gives rise to a current system producing an auroral footprint in Jupiter's ionosphere, usually referred to as the Ganymede footprint. Based on an analysis of ultraviolet images obtained with the Hubble Space Telescope, we demonstrate that the auroral footprint surface m…
Mutual orbits and masses of six transneptunian binaries
Buie, M. W.; Grundy, W. M.; Noll, K. S. +3 more
We present Hubble Space Telescope observations of six binary transneptunian systems: 2000 QL 251, 2003 TJ 58, 2001 XR 254, 1999 OJ 4, (134860) 2000 OJ 67, and 2004 PB 108. The mutual orbits of these systems are found to have periods ranging from 22 to 137 days, semimajor axes rangin…
A multiwavelength investigation of the massive eclipsing binary Cygnus OB2 #5
Damerdji, Y.; Rauw, G.; Vreux, J. -M. +5 more
Context: The properties of the early-type binary
Aims: We have attempted to constrain the physical properties of the binary by collecting new optical and X-ray observations.
Methods: The optical light…
Solar Magnetic Helicity Injected into the Heliosphere: Magnitude, Balance, and Periodicities Over Solar Cycle 23
Georgoulis, M. K.; Pevtsov, A. A.; Rust, D. M. +2 more
Relying purely on solar photospheric magnetic field measurements that cover most of solar cycle 23 (1996-2005), we calculate the total relative magnetic helicity injected into the solar atmosphere, and eventually shed into the heliosphere, over the latest cycle. Large active regions dominate the helicity injection process with ~5.7 × 1045
Characterization of Clouds in Titan's Tropical Atmosphere
Sotin, Christophe; Le Mouélic, Stéphane; Rodriguez, Sebastien +7 more
Images of Titan's clouds, possible over the past 10 years, indicate primarily discrete convective methane clouds near the south and north poles and an immense stratiform cloud, likely composed of ethane, around the north pole. Here we present spectral images from Cassini's Visual Mapping Infrared Spectrometer that reveal the increasing presence of…
Evolution of Optical Penumbral and Shear Flows Associated with the X3.4 Flare of 2006 December 13
Wang, Haimin; Chen, P. F.; Abramenko, Valentyna +1 more
The rapid and irreversible decay of penumbrae related to X-class flares has been found in a number of studies. Since the optical penumbral flows are closely associated with the morphology of sunspot penumbra, we use state-of-the-art Hinode data to track penumbral flows in flaring active regions as well as shear flows close to the flaring neutral l…
Benchmarking atomic data for astrophysics: Fe VIII EUV lines
Del Zanna, G.
The EUV spectrum of ion{Fe}{viii} is reviewed, using new solar observations from the Hinode EUV Imaging Spectrometer (EIS), together with older solar and laboratory data. The most up-to-date scattering calculations are benchmarked against these experimental data, with the use of a large atomic structure calculation. Once adjustments are made to th…
Characterization of auroral current systems in Saturn's magnetosphere: High-latitude Cassini observations
Coates, A. J.; Dougherty, M. K.; Cowley, S. W. H. +3 more
We have identified seven periapsis passes during the first high-latitude phase of the Cassini mission, from mid-2006 to mid-2007, in which the spacecraft traversed at intermediate altitudes the region between open field lines at highest latitudes and the region inside the inner edge of the ring current. Varying azimuthal magnetic fields indicative…
Visible and near-infrared nightglow of molecular oxygen in the atmosphere of Venus
Drossart, P.; Piccioni, G.; García Muñoz, A. +2 more
The Herzberg II system of O2 has been a known feature of Venus' nightglow since the Venera 9 and 10 orbiters detected its c(0)-X(v″) progression more than 3 decades ago. We search for its emission at 400 nm-700 nm in spectra obtained with the VIRTIS instrument on Venus Express. Despite the weakness of the signal, integration over a few …
Model of Saturn's internal planetary magnetic field based on Cassini observations
Russell, C. T.; Dougherty, M. K.; Burton, M. E.
We have derived a model of Saturn's internal planetary magnetic field from data obtained during the first three years of the Cassini Mission. This model is based on the most complete set of observations yet obtained in Saturn's magnetosphere and includes data from forty-five periapsis passes at a wide variety of geometries. Due to uncertainties in…