Search Publications
Methane depletion in both polar regions of Uranus inferred from HST/STIS and Keck/NIRC2 observations
Sromovsky, L. A.; Fry, P. M.; Karkoschka, E. +3 more
From Space Telescope Imaging Spectrograph (STIS) observations of Uranus in 2012, when good views of its north polar regions were available, we found that the methane volume mixing ratio declined from about 4% at low latitudes to about 2% at 60-80°N. This depletion in the north polar region of Uranus in 2012 is similar in magnitude and depth to tha…
Open flux in Saturn’s magnetosphere
Gérard, Jean-Claude; Clarke, John T.; Badman, Sarah V. +2 more
We characterise the interaction between the solar wind and Saturn's magnetosphere by evaluating the amount of 'open' magnetic flux connected to the solar wind. This is deduced from a large set of Hubble Space Telescope images of the ultraviolet aurora, using the poleward boundary of the main aurora as a proxy for the open-closed field line boundar…
Physical and dynamical properties of the main belt triple Asteroid (87) Sylvia
Berthier, J.; Carry, B.; Marchis, F. +2 more
We present the analysis of high angular resolution observations of the triple Asteroid (87) Sylvia collected with three 8-10 m class telescopes (Keck, VLT, Gemini North) and the Hubble Space Telescope. The moons’ mutual orbits were derived individually using a purely Keplerian model. We computed the position of Romulus, the outer moon of the syste…
In-flight calibration of the Dawn Framing Camera II: Flat fields and stray light correction
Mottola, S.; Matz, K. -D.; Schröder, S. E. +1 more
The NASA Dawn spacecraft acquired thousands of images of asteroid Vesta during its year-long orbital tour, and is now on its way to asteroid Ceres. A method for calibrating images acquired by the onboard Framing Camera was described by Schröder et al. (Schröder et al. [2013]. Icarus 226, 1304). However, their method is only valid for point sources…
A phenomenological model of Io's UV aurora based on HST/STIS observations
Saur, Joachim; Roth, Lorenz; Feldman, Paul D. +2 more
We have carried out a comprehensive analysis of a large set of spatially resolved observations of Io's OI 1304 Å, OI] 1356 Å, SI 1479 Å and SI] 1900 Å aurora taken by the Space Telescope Imaging Spectrograph (STIS) of the Hubble Space Telescope (HST) between 1997 and 2001. We find that the variability of the observed morphologies can be solely exp…
Noncircular features in Saturn's rings I: The edge of the B ring
Nicholson, Philip D.; French, Richard G.; Hedman, Matthew M. +2 more
A comprehensive investigation of all available radio and stellar occultation data for the outer edge of Saturn's B ring, spanning the period 1980-2010, confirms that the m = 2 distortion due to the strong Mimas 2:1 inner Lindblad resonance circulates slowly relative to Mimas in a prograde direction, with a frequency ΩL = 0.1819° d-…
Multiple asteroid systems (45) Eugenia and (87) Sylvia: Sensitivity to external and internal perturbations
Marchis, F.; Beauvalet, L.
Satellites of asteroids are a widely used way to determine the masses and other dynamical parameters of their systems. We make such a determination here, using data from the two triple-asteroid systems, (45) Eugenia and (87) Sylvia, that come from the Hubble Space Telescope and adaptive optics on three 8-10 m class telescopes (Keck, VLT, Gemini No…
Dayglow and auroral emissions of Uranus in H2 FUV bands
Lamy, L.; Roueff, E.; Cessateur, G. +7 more
Following the recent detection of an auroral signal on Uranus (Lamy et al. [2012]. Geophys. Res. Lett. 39, 7105) during HST/STIS observation performed in November 2011, we analyzed the associated HST/STIS FUV spectral images obtained in 2011 and 2012. Our purpose was to extract any possible H2 emission produced in the upper atmosphere o…
The orbit of transneptunian binary Manwë and Thorondor and their upcoming mutual events
Grundy, W. M.; Noll, K. S.; Benecchi, S. D. +1 more
A new Hubble Space Telescope observation of the 7:4 resonant transneptunian binary system (385446) Manwë has shown that, of two previously reported solutions for the orbit of its satellite Thorondor, the prograde one is correct. The orbit has a period of 110.18 ± 0.02 days, semimajor axis of 6670 ± 40 km, and an eccentricity of 0.563 ± 0.007. It w…