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 report near-infrared observations of Prometheus and Janus taken on 9 and 13 November 2000 (UT) with the Palomar Adaptive Optics System on the 5-m Hale telescope at Palomar Observatory. Dione, Rhea, and Tethys were used as guide ''stars'' for the adaptive optics system, and, though they were outside the isoplanatic patch of the region of interest, they allowed significant correction of the atmospheric...
Irregular satellites-moons that occupy large orbits of significant eccentricity e and/or inclination I-circle each of the giant planets. The irregulars often extend close to the orbital stability limit, about 1/3-1/2 of the way to the edge of their planet's Hill sphere. The distant, elongated, and inclined orbits suggest capture, which presumably would give a random distribution of inclinations. Yet,...
The occultation of GSC5249-01240 by Saturn's rings was observed in a spectrally resolved mode using the Faint Object Spectrograph on the Hubble Space Telescope. By combining these data with other occultation data, we have determined the inclination of the F ring to be 0.0065+/-0.0014 deg. Our inclined F ring orbit model explains an abrupt decrease in flux at the west ansa of the ring that was observed...
Observations at 2.3 μm at the Australian National University 2.3-m telescope at Siding Spring Observatory and the 5-m Hale telescope at Palomar Observatory from 9 to 17 August provide a longer baseline of time around the 10 August 1995 Saturn ring-plane crossing than space-based observations. The edge-on photometric thickness of the rings at a wavelength of 2.34 μm is determined to be 0.7+/-0.1 km,...
In May, August, and November 1995, Hubble Space Telescope (HST) observations during Saturn's ring-plane crossings allowed us to view saturnian satellites normally hidden to Earth-based observers in the glare of the rings. New measurements of Janus, Epimetheus, Prometheus, and Pandora have been combined to form revised orbital solutions using all three HST data sets. These measurements and orbit fits...
Photometrically calibrated grism spectra of Saturn in the H-(1.45-1.80 μm) and K-band (1.95-2.50 μm) are presented. The spectra were obtained with the 200-inch Hale telescope at Palomar mountain three days after the ring plane crossing of August 10, 1995. By inversion of the spectra, the vertical distribution of the scattering density is obtained as a function of latitude along the central meridian,...
The icy moons of Jupiter, Europa, Ganymede, and Callisto, are efficient backscatterers of centimeter-wavelength radiation. At 3.5-cm and 13-cm wavelengths their specific radar cross sections can exceed unity (Campbell et al. 1978, Icarus34, 254-267, Ostro et al. 1992, J. Geophys. Res.97, 18227-18244), while by 70-cm wavelength their cross sections have dropped considerably (Black et al. 2001) though...
We report the first detection and profile characterization of thermal emission from the surface of Venus at 0.85 and 0.90 μm, observed in the first planetary spectrum acquired by the Visual-Infrared Mapping Spectrometer onboard the Cassini spacecraft en route to the Saturn system. The strength and shape of these two newly observed nightside emissions agree with theoretical predictions based on the...
We present optical depth profiles for Saturn's rings at wavelengths of 0.9, 2.1, 3.3, and 3.9 μm, obtained from the occultation of the star 28 Sgr on 3 July 1989 when the rings were near their maximum opening angle. The radial resolution of the data is ~18 km, as set by the angular diameter of the star. Very few, if any, structural changes are observed in the rings since the Voyager encounters in...
We derive power-law particle size distributions for each of Saturn's main ring regions, using observations of the 3 July 1989 stellar occultation of 28 Sgr from Palomar, McDonald, and Lick observatories. We use the Voyager PPS δ Sco optical depth profile to estimate and then remove the directly transmitted signal from the 28 Sgr observations, leaving high SNR scattered light profiles at wavelengths...
We analyze observations made in August and November 1995 during the Earth and Sun crossings of Saturn's ring plane, respectively. The August 1995 observations combine data taken with the Adonis adaptive optics system at the European Southern Observatory (ESO) and images from the Hubble Space Telescope (HST). The November 1995 data are based on HST images only. We report here the detections of four...
We imaged the jovian ring system at a wavelength of 2.27 μm with the 10-m W. M. Keck telescope on August 14 and 15, 1997, when the ring plane was almost edge-on (opening angle β=0.17°) and near opposition (phase angle α≈1.1°). The resolution in the images is 0.6″=0.025R J . We obtained the first images of the jovian halo and gossamer ring in back-scattered light, and the best ground-based...
Photometrically calibrated grism spectra of Jupiter in the H (1.45–1.8 μm) and K (1.95–2.5 μm) bands with a resolution of about 100 were taken with the 5-m Hale telescope at Palomar in August of 1995. The spectra were obtained as meridional cuts at six different longitudes on the planet, with one cut crossing the Great Red Spot.The technique outlined in D. Banfieldet al.(1996,Icarus121, 389–410) for...
Using the SpectroCam-10 instrument on the Hale 200'' telescope at Palomar Observatory, we obtained an extensive set of images and spectra of Mars in the thermal infrared during the 1993 and 1995 oppositions. Images were taken using a set of seven wide-band filters centered at 7.9, 8.8, 9.8, 10.3, 11.7, 12.5, and 17.9 μm. Spatially resolved slit spectra with a spectral resolving power of λ/Δλ = 100...
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.