The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We present observations of the uranian ring system at a wavelength of 2.2μm, taken between 2003 and 2008 with NIRC2 on the W.M. Keck telescope in Hawaii, and on 15–17 August 2007 with NaCo on the Very Large Telescope (VLT) in Chile. Of particular interest are the data taken around the time of the uranian ring plane crossing with Earth on 16 August 2007, and with the Sun (equinox) on 7 December 2007...
We present a Monte Carlo model of the uranian rings, and compare this model to images of the system obtained with the Keck adaptive optics system in July 2004, at a wavelength of 2.2μm (from de Pater et al. (de Pater, I., Gibbard, S.G., Hammel, H.B. [2006a]. Icarus 180, 186–200)). We confirm the presence of the ζ ring, but show that this ring must extend inwards much further than previously thought,...
Over the last 15 to 20 years several high quality, high resolution data have been taken with the very large array (VLA). These data exhibit a wide range of ring opening angles (|B|=0 to 26°) and wavelengths (λ=0.7 to 20 cm). At these wavelengths the primary flux from the rings is scattered saturnian thermal emission, with a small contribution coming from the ring particles' own thermal emission. Much...
We present a new Very Large Array (VLA) image of Saturn, made from data taken in October 1998 at a wavelength of λ3.6 cm. The moderate ring opening angle (B~15 o ) allows us to explore direct transmission of microwave photons through the A and C rings. We find a strong asymmetry of photons transmitted through the A ring, but not in the C ring, a new diagnostic of wake structure in the ring...
We present a summary of Jupiter data taken over an eighteen year span (1981-1998) by the Very Large Array at ~21.0 cm. At this wavelength the emission is dominated by synchrotron radiation, which is roughly proportional to the product of the electron number density and magnetic field strength (N e B). At each epoch 8-12 hours of data were taken, which allowed us to examine Jupiter during an...
We observed Jupiter's synchrotron radiation at frequencies of 15 and 22 GHz using the VLA (Very Large Array) in its most compact configuration (D-array) in March 1991. The spatial brightness distribution of the emission at these high frequencies appears to be very similar to that seen at lower frequencies (5 GHz down to 330 MHz). We measured a total nonthermal flux density at 15 and 22 GHz of 1.5...
We present a second epoch of Very Large Array Saturn observations taken in February 1997 spanning wavelengths 1.3-21 cm. These observations complement earlier observations at Saturn's autumnal equinox in November 1995. In this epoch, however, we generally have better signal-to-noise ratios and the ring inclination of the present observations was -5.0 o , whereas the previous observations were...
We present evidence of an unusual and previously unidentified feature in Saturn's outer B ring at a radius of 117,130 km. The Voyager 2 optical occultation experiment shows a step in opacity, dropping from 1.4 to 0.5 across several kilometers and generally remaining low out to the edge of the ring. By contrast, the Voyager 1 radio occultation showed no distinct change at this location, a rare lack...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.