Search Publications
The dynamic neptunian ring arcs: evidence for a gradual disappearance of Liberté and resonant jump of courage
de Pater, Imke; Macintosh, Bruce; Marchis, Franck +6 more
We present Adaptive Optics observations of Neptune's ring system at 1.6 and 2.2 µm, taken with the 10-m W.M. Keck II telescope in July 2002 and October 2003. We recovered the full Adams and Le Verrier rings for the first time since the Voyager era (1989), and show that the overall appearance of these rings did not change much, except for the…
Accurate and approximate calculations of Raman scattering in the atmosphere of Neptune
Sromovsky, L. A.
Raman scattering by H 2 in Neptune's atmosphere has significant effects on its reflectivity for λ<0.5 µm, producing baseline decreases of ∼20% in a clear atmosphere and ∼10% in a hazy atmosphere. However, few accurate Raman calculations are carried out because of their complexity and computational costs. Here we present the fir…
Secular light curve of Comet 28P/Neujmin 1 and of spacecraft target Comets 1P/Halley, 9P/Tempel 1, 19P/Borrelly, 21P/Giacobinni Zinner, 26P/Grigg Skjellerup, 67P/Churyumov Gerasimenko, and 81P/Wild 2
Ferrín, Ignacio
We present the secular light curves of eight comets listed in the title. Two plots per comet are needed to study these objects: a reduced magnitude (to Δ=1 AU = geocentric distance) vs time, and a reduced magnitude vs Log R ( R=heliocentric distance). A total of over 16 new parameters, are measured from both plots, and give an unprecedented amount…
HST observations of spokes in Saturn's B ring
French, Richard G.; Salo, Heikki J.; Dones, Luke +3 more
As part of a long-term study of Saturn's rings, we have used the Hubble Space Telescope's (HST) Wide Field and Planetary Camera (WFPC2) to obtain several hundred high resolution images from 1996 to 2004, spanning the full range of ring tilt and solar phase angles accessible from the Earth. Using these multiwavelength observations and HST archival …
Condensate clouds in Titan's north polar stratosphere
Samuelson, Robert E.; Mayo, Louis A.
Analysis of the 250-560 cm -1 spectral continuum of Titan's north polar hood just after spring equinox reveals, in addition to the ubiquitous aerosol, a tenuous but relatively uniform cloud of small particles permeating the lower stratosphere at altitudes between 58 and 90 km. Voyager 1 IRIS data suggest the particles are highly scatter…
Carbon monoxide fluorescence from Titan's atmosphere
Lellouch, E.; López-Valverde, M. A.; Coustenis, A.
We report on the discovery of emissions due to carbon monoxide from Titan's atmosphere, from mid-infrared observations with the ISAAC spectrometer at the Very Large Telescope and covering the 4.50-4.85 µm range. We detected about 45 emission lines coinciding with CO ro-vibrational lines, including CO(1-0) (P18 to R11) and CO(2-1) (P11 to R11…
Jupiter's cyclones and anticyclones vorticity from Voyager and Galileo images
Sánchez-Lavega, A.; Legarreta, J.
We have measured the internal velocity field in jovian synoptic-scale cyclones and anticyclones by tracking cloud elements in very high spatial resolution images obtained by the Voyager 1 and 2 (in 1979) and Galileo (1996-2000) spacecrafts. In total we have studied 24 different closed vortices (6 cyclones, 18 anticyclones) spanning a latitude rang…
Temporal deconvolution of the hydrogen coma. II. Pre- and post-perihelion activity of Comet Hyakutake (1996 B2)
Bertaux, J. -L.; Combi, M. R.; Mäkinen, J. T. T. +1 more
Comet 1996 B2 (Hyakutake) displayed strong evidence for break-up, with a prominent antisunward dust spike and fragments traveling antisunward for many days after an eruptive event in late March 1996. Because of its high orbital inclination and rapid southward motion after perihelion, its post-perihelion activity was not well monitored from the gro…
Maps of Titan's surface from 1 to 2.5 µm
Drossart, Pierre; Coustenis, Athena; Lai, Olivier +4 more
We have acquired resolved images of Titan with the adaptive optics systems PUEO/KIR at the CFHT (Hawaii) and NAOS/CONICA at the VLT (Chile). We report here on images and maps (when data at several orbital phases are available) of Titan's surface from observations taken during the last 4 years (2001-2004) in all the methane windows between 1 and 2.…
Expectations for Cassini observations of ring material with nearby moons
Lewis, Mark C.; Stewart, Glen R.
This paper describes N-body simulations of two regions of the saturnian ring system and examines what we might expect the Cassini orbiter to see in those areas. The first region is the edge of the Encke gap in the A ring that is perturbed by the satellite, Pan. Our previous simulations of this region neglected particle self-gravity [Lewis and Stew…