Search Publications

Microstructural penetrometry of asteroid regolith analogues and Titan's surface

Green, S. F.; Ball, A. J.; Paton, M. D.

We investigate essential aspects of penetrometer design required to measure particle properties on asteroids using a combination of laboratory analogue regoliths and spaceflight data returned by the Huygens probe from Titan. Penetrometry in granular material is complicated due to multiple and interdependent mechanical processes that occur during p…

Anomalous Resistivity Associated with Secondary Islands in the Reconnection Region

Zhou, Meng; Deng, Xiao-Hua; Su, Wei +1 more

We calculate the anomalous resistivity (AR) due to electrostatic waves, including possibly the lower hybrid wave and electron beam mode, around the secondary islands in the reconnection region observed by the Cluster spacecraft. Our main findings are: AR is important on the reconnection separatrix layer but heavily suppressed at the central curren…

Radiation transfer in the cavity and shell of a planetary nebula

Zijlstra, A. A.; Gray, M. D.; Matsuura, M.

We develop an approximate analytical solution for the transfer of line-averaged radiation in the hydrogen recombination lines for the ionized cavity and molecular shell of a spherically symmetric planetary nebula. The scattering problem is treated as a perturbation, using a mean intensity derived from a scattering-free solution. The analytical fun…

French instruments for in-situ missions: Past, present and future

Gaudon, Philippe; Bousquet, Pierre W.; Gaboriaud, Alain +3 more

Two in-situ missions were launched at the end of 2011, soon after the 62nd IAC conference, one to Mars and the other to one of its moons, Phobos. The first - Mars Science Laboratory - has been developed by NASA and will take the largest ever rover, Curiosity, to the surface of Mars. The second mission, Phobos-Grunt under the responsibility of Rosc…

On the Passive Nature of Proton Temperature in Solar Wind Turbulence

Consolini, Giuseppe

In the framework of space plasma physics the solar wind is commonly recognized as an example of turbulent medium. Although turbulence studies mainly focalize on the features of velocity field (and magnetic field for plasma media), another field of investigation deals with the properties of scalar quantities (such as the concentrations of tracers, …

SARIM PLUS—sample return of comet 67P/CG and of interstellar matter

Altwegg, K.; Dikarev, V.; Kempf, S. +58 more

The Stardust mission returned cometary, interplanetary and (probably) interstellar dust in 2006 to Earth that have been analysed in Earth laboratories worldwide. Results of this mission have changed our view and knowledge on the early solar nebula. The Rosetta mission is on its way to land on comet 67P/Churyumov-Gerasimenko and will investigate fo…

Studies of a possible new Herbig Ae/Be star in the open cluster NGC 7380

Mathew, Blesson; Banerjee, D. P. K.; Subramaniam, Annapurni +3 more

We present a study of the star 2MASS J22472238+5801214 with the aim of identifying its true nature which has hitherto been uncertain. This object, which is a member of the young cluster NGC 7380, has been variously proposed to be a Be star, a D-type symbiotic and a Herbig Ae/Be star in separate studies. Here we present optical spectroscopy, near-I…

Cassini Spies an Ocean Inside Saturn's Icy, Gassy Moon Titan

Kerr, Richard A.

Unusual Emissions at Various Energies Prior to the Impulsive Phase of the Large Solar Flare and Coronal Mass Ejection of 4 November 2003

Su, Yang; Holman, Gordon D.; Kaufmann, Pierre +6 more

The GOES X28 flare of 4 November 2003 was the largest ever recorded in its class. It produced the first evidence for two spectrally separated emission components, one at microwaves and the other in the THz range of frequencies. We analyzed the pre-flare phase of this large flare, twenty minutes before the onset of the major impulsive burst. This p…

CO observations of water-maser post-asymptotic giant branch stars and detection of a high-velocity outflow in IRAS 15452-5459

Menten, K. M.; Cerrigone, L.; Kamiński, T.

Many aspects of the evolutionary phase in which asymptotic giant branch stars (AGB stars) are in transition to become planetary nebulae (PNe) remain poorly understood. An important question is how the circumstellar envelopes of AGB stars switch from spherical symmetry to the axially symmetric structures frequently observed in PNe. In many cases, t…