Search Publications
Constraints on Mimas’ interior from Cassini ISS libration measurements
Charnoz, S.; Lainey, V.; Noyelles, B. +4 more
Like our Moon, the majority of the solar system’s satellites are locked in a 1:1 spin-orbit resonance; on average, these satellites show the same face toward the planet at a constant rotation rate equal to the satellite’s orbital rate. In addition to the uniform rotational motion, physical librations (oscillations about an equilibrium) also occur.…
New Evidence for a Substellar Luminosity Problem: Dynamical Mass for the Brown Dwarf Binary Gl 417BC
Dupuy, Trent J.; Ireland, Michael J.; Liu, Michael C.
We present new evidence for a problem with cooling rates predicted by substellar evolutionary models that implies that model-derived masses in the literature for brown dwarfs and directly imaged planets may be too high. Based on our dynamical mass for Gl 417BC (L4.5+L6) and a gyrochronology system age from its young, solar-type host star, commonly…
Interaction of magnetic reconnection and Kelvin-Helmholtz modes for large magnetic shear: 1. Kelvin-Helmholtz trigger
Ma, Xuanye; Otto, Antonius; Delamere, Peter A.
At the Earth's magnetopause, both magnetic reconnection and the Kelvin-Helmholtz (KH) instability can operate simultaneously for southward interplanetary magnetic field conditions. The dynamic evolution of such a system can be expected to depend on the importance of KH wave evolution versus reconnection and therefore on the respective initial pert…
Herschel view of the large-scale structure in the Chamaeleon dark clouds
Prusti, T.; Pilbratt, G. L.; André, Ph. +17 more
Context. The Chamaeleon molecular cloud complex is one of the nearest star-forming sites and encompasses three molecular clouds (Cha I, II, and III) that have a different star-formation history, from quiescent (Cha III) to actively forming stars (Cha II), and one that reaches the end of star-formation (Cha I).
Aims: We aim at characterising t…
Observational Characteristics of Coronal Mass Ejections without Low-coronal Signatures
Berghmans, D.; Seaton, D. B.; D'Huys, E. +1 more
Solar eruptions are usually associated with a variety of phenomena occurring in the low corona before, during, and after the onset of eruption. Though easily visible in coronagraph observations, so-called stealth coronal mass ejections (CMEs) do not obviously exhibit any of these low-coronal signatures. The presence or absence of distinct low-coro…
New Evidence for Efficient Collisionless Heating of Electrons at the Reverse Shock of a Young Supernova Remnant
Petre, Robert; Yamaguchi, Hiroya; Hughes, John P. +7 more
Although collisionless shocks are ubiquitous in astrophysics, certain key aspects of them are not well understood. In particular, the process known as collisionless electron heating, whereby electrons are rapidly energized at the shock front, is one of the main open issues in shock physics. Here, we present the first clear evidence for efficient c…
Saturn's dynamic magnetotail: A comprehensive magnetic field and plasma survey of plasmoids and traveling compression regions and their role in global magnetospheric dynamics
Dougherty, M. K.; Thomsen, M. F.; Jackman, C. M. +8 more
We present a comprehensive study of the magnetic field and plasma signatures of reconnection events observed with the Cassini spacecraft during the tail orbits of 2006. We examine their "local" properties in terms of magnetic field reconfiguration and changing plasma flows. We also describe the "global" impact of reconnection in terms of the contr…
On the progenitor of the Type IIP SN 2013ej in M74.
Gal-Yam, A.; Inserra, C.; Smartt, S. J. +10 more
We use natural seeing imaging of SN 2013ej in M74 to identify a progenitor candidate in archival Hubble Space Telescope (HST) + Advanced Camera for Survey images. We find a source coincident with the supernova (SN) in the F814W filter within the total 75 mas (∼3 pc astrometric uncertainty; however, the position of the progenitor candidate in conte…
LOFAR tied-array imaging of Type III solar radio bursts
Magdalenić, J.; McKean, J. P.; Eislöffel, J. +82 more
Context. The Sun is an active source of radio emission which is often associated with energetic phenomena such as solar flares and coronal mass ejections (CMEs). At low radio frequencies (<100 MHz), the Sun has not been imaged extensively because of the instrumental limitations of previous radio telescopes.
Aims: Here, the combined high sp…
Revisiting the transits of CoRoT-7b at a lower activity level
Aigrain, S.; Alonso, R.; Bordé, P. +29 more
The first super-Earth with measured radius discovered was CoRoT-7b and it has opened the new field of rocky exoplanet characterisation. To better understand this interesting system, new observations were taken with the CoRoT satellite. During this run 90 new transits were obtained in the imagette mode. These were analysed together with the previou…