Search Publications
Surface charging of Saturn's plasma-absorbing moons
Krupp, N.; Jones, G. H.; Roussos, E. +1 more
Recent results from the study of the interaction of Earth's moon with the solar wind have highlighted lunar surface charging as an important physical process not only for the local interaction of the surface and the impinging plasma but also for charged dust ejection and transport. Excluding Earth's moon, however, such studies have been limited to…
Heliospheric Energetic Particle Reservoirs: Ulysses and ACE 175-315 keV Electron Observations
Lario, D.
Heliospheric energetic particle reservoirs are usually observed in the decay phase of large solar energetic particle (SEP) events when particle intensities measured by widely separated spacecraft (in longitude, latitude and radial distance) present comparable intensities (within a factor of 2-3) that evolve similarly in time. We use near-relativis…
2MASS J03105986 +1648155 AB - a new binary at the L/T transition
Bouy, H.; Henning, Th.; Brandner, W. +2 more
Context. The transition from the L to the T spectral type of brown dwarfs is marked by a very rapid transition phase, remarkable brightening in the J-band, and higher binary frequency. Despite being an active area of inquiry, this transition region still remains one of the most poorly understood phases of brown dwarf evolution.
Aims: We resol…
An Optical-infrared Study of the Young Multipolar Planetary Nebula NGC 6644
Zhang, Yong; Volk, Kevin; Kwok, Sun +2 more
High-resolution Hubble Space Telescope imaging of the compact planetary nebula NGC 6644 has revealed two pairs of bipolar lobes and a central ring lying close to the plane of the sky. From mid-infrared imaging obtained with the Gemini Telescope, we have found a dust torus which is oriented nearly perpendicular to one pair of the lobes. We suggest …
Tiny Pores Observed by Hinode/Solar Optical Telescope
Chae, Jongchul; Cho, Kyung-Suk; Kim, Yeon-Han +2 more
The study of pores, small penumbraless sunspots, can give us a chance to understand how strong magnetic fields interact with convective motions in the photosphere. For a better understanding of this interaction, we investigate the temporal variation of several tiny pores smaller than 2''. These pores were observed by the Solar Optical Telescope on…
Sublimation of the Martian CO 2 Seasonal South Polar Cap
Bibring, Jean-Pierre; Langevin, Yves; Martin, Patrick +6 more
The polar condensation/sublimation of CO 2, that involve about one fourth of the atmosphere mass, is the major Martian climatic cycle. Early observations in visible and thermal infrared have shown that the sublimation of the Seasonal South Polar Cap (SSPC) is not symmetric around the geographic South Pole. Here we use observations by OM…
Source mechanism of Saturn narrowband emission
Cecconi, B.; Menietti, J. D.; Rymer, A. M. +2 more
Narrowband emission (NB) is observed at Saturn centered near 5 kHz and 20 kHz and harmonics. This emission appears similar in many ways to Jovian kilometric narrowband emission observed at higher frequencies, and therefore may have a similar source mechanism. Source regions of NB near 20 kHz are believed to be located near density gradients in the…
Orbit Determination of Double-lined Spectroscopic Binaries by Fitting the Revised Hipparcos Intermediate Astrometric Data
Ren, Shulin; Fu, Yanning
Untill now, the Hipparcos intermediate astrometric data (HIAD) have contributed little to the full orbit determination of double-lined spectroscopic binaries (SB2s). This is because the photocenter of such a binary system is usually not far from the system mass center, and its orbital wobble is generally weak with respect to the accuracy of the HI…
Comparison of eight years magnetic field data from Cluster with Tsyganenko models in the inner magnetosphere
Woodfield, E. E.; Dunlop, M. W.; Zhang, Q. -H. +1 more
Eight years of magnetic field data, taken while the four Cluster spacecraft pass through, or adjacent to, the equatorial ring current, have been surveyed to investigate the effects on the Earth's magnetic field of the externally driven current systems connecting the ionosphere, cusp and ring current regions. This study extends previous work to cov…
A multilayer model for thermal infrared emission of Saturn’s rings II: Albedo, spins, and vertical mixing of ring particles inferred from Cassini CIRS
Altobelli, Nicolas; Spilker, Linda; Ohtsuki, Keiji +3 more
Since the Saturn orbit insertion of the Cassini spacecraft in mid-2004, the Cassini composite infrared spectrometer (CIRS) measured temperatures of Saturn's main rings at various observational geometries. In the present study, we apply our new thermal model (Morishima, R., Salo, H., Ohtsuki, K. [2009]. Icarus 201, 634-654) for fitting to the early…