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Infrared Space Observatory (ISO) data of Jupiter are revisited in order to derive CH 4 mixing ratios at microbar pressures in the atmosphere. We utilize the most updated radiative transfer programs to construct a 3-μm emission model of CH 4 to be compared with the ISO data. From the model-data comparisons, we derive the high-altitude CH 4 mixing ratios, which turn out to be...
We present observational data for Comet 9P/Tempel 1 taken from 1997 through 2010 in an international collaboration in support of the Deep Impact and Stardust-NExT missions. The data were obtained to characterize the nucleus prior to the Deep Impact 2005 encounter, and to enable us to understand the rotation state in order to make a time of arrival adjustment in February 2010 that would allow us to...
The evolution of the spin rate of Comet 9P/Tempel 1 through two perihelion passages (in 2000 and 2005) is determined from 1922 Earth-based observations taken over a period of 13year as part of a World-Wide observing campaign and from 2888 observations taken over a period of 50 days from the Deep Impact spacecraft. We determine the following sidereal spin rates (periods): 209.023±0.025°/dy (41.335±0...
We present latitudinally-resolved high-resolution (R=37,000) pole-to-pole spectra of Jupiter in various narrow longitudinal ranges, in spectral intervals covering roughly half of the spectral range 2.86–3.53μm. We have analyzed the data with the aid of synthetic spectra generated from a model jovian atmosphere that included lines of CH 4 , CH 3 D, NH 3 , C 2 H 2...
Jupiter exhibits bright H+3 auroral arcs at 3–4 microns that cool the hot (>1000 K) ionosphere above the ∼10−7 bar level through the infrared bands of this trace constituent. Below the 10−7 bar level significant cooling proceeds through infrared active bands of CH4, C2H2, and C2H6. We report the discovery of 3-micron line emission from these hydrocarbon species in spectra of the jovian south polar...
We have constructed synthetic solar spectra for the 2302–4800 cm −1 (2.08–4.34 μm) range, a spectral range where planetary objects mainly emit reflected sunlight, using ATMOS (Atmospheric Trace Molecule Spectroscopy)/Spacelab-3 and Atlas-3 spectra, of which resolution is 0.01 cm −1 . We adopted Voigt line profiles for the modeling of line shapes based on an atlas of line identifications...
We report observation and analysis of a high-resolution 2.87–3.54 μm spectrum of the southern temperate region of Saturn obtained with NIRSPEC at Keck II. The spectrum reveals absorption and emission lines of five molecular species as well as spectral features of haze particles. The ν2+ν3 band of CH 3 D is detected in absorption between 2.87 and 2.92 μm; and we derived from it a mixing ratio...
We have used synthetic spectra to analyze a medium resolution 2.9–4.2 μm spectrum of Saturn's temperate region observed at UKIRT using CGS4. The synthetic spectra include CH 4 , PH 3 , and NH 3 lines, for which mixing ratios were adopted from recent Cassini results. The observed absorption features in the spectrum are well accounted for by lines of these molecular species formed...
Using synthetic spectra derived from an updated model atmosphere together with a continuum model that includes contributions from haze, cloud and ground, we have re-analyzed the recently published (Geballe et al., 2003, Astrophys. J. 583, L39–L42) high-resolution 3 μm spectrum of Titan which contains newly-detected bands of HCN (in emission) and C 2 H 2 and CH 3 D (in absorption),...
We have constructed line-by-line fluorescence models for the ro-vibrational bands of the B–X system of sulfur dimers (S 2 ). For the first time the detailed rotational lines of the bands are clearly resolved in the high-resolution echelle spectra of Comet Hyakutake (C/1996 B2), which were obtained at the Kitt Peak 4-m telescope on 26.4 March 1996 (UT). In order to construct satisfactory band...
We obtained high resolution (λ/δλ~10,000-20,000) infrared (IR) spectra of Comet 21P/Giacobini-Zinner (GZ) at five different wavelengths between 1.9 and 5.0 μm during 25-29 October 1998 using CSHELL at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea. We also obtained a moderate resolution (λ/δλ~680) spectrum covering the wavelength range from 3.082 to 3.720 μm on 29 October 1998 using CGS4...
Comet Hyakutake was an ideal target for studying the near-nuclear region of a bright comet. On 1996 March 26.3–26.5 (UT) we observed the comet with an echelle spectrometer at the 4-m telescope atop Kitt Peak. High-resolution spectra of NH and CH are presented and compared with fluorescence models. At a spectral resolution of Δλ ≤ 0.2 Å two multiplets of ND are not blended by the overlying NH line...
We report the detection of the (H 2 ) 2 dimer in the atmospheres of Saturn and Neptune based on spectra of the fundamentalS 1 (1) collision-induced band of H 2 . The lines of this dimer are potentially useful for probing the (H 2 ) 2 ortho–para ratio and its implications for atmospheric dynamical processes. We also report the detection of the (1–0)S...
Infrared spectra of Jupiter's atmosphere were obtained with the infrared spectrometer (IRS) on the 1.5-m telescope at the Cerro Tololo Inter-American Observatory (CTIO) during the first 2 days of the impacts of the fragments of Comet Shoemaker–Levy 9 (1993e). We monitored 3.51 ± 0.17 μm radiation from the impact areas, undisturbed areas, and auroral regions of Jupiter after the A and E impacts. The...
Spectra of the 4-μm continuum of the polar regions of Jupiter were obtained at the Canada-France-Hawaii Telescope. These spectra were compared with a low-resolution spectrum of the equatorial region obtained at the United Kingdom Infrared Telescope. The comparison shows that the continuum level of the equatorial spectrum is at least five times higher than those of the polar spectra. It was also found...
Recent high-resolution 2.10- to 2.13-μm equatorial spectra of Jupiter show several prominent absorption lines in addition to a narrow H 2 1-0 S(1) absorption. Comparison with laboratory spectra of the H 2 dimer reveals excellent wavelength coincidences with five of the jovian absorptions. We conclude that the jovian lines are due to the H 2 dimer. No other jovian lines are...
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