[en] The CH³D molecule is an intermediate methane which has immediate importance in the study of the chemical composition of the outer planets. The deuterium present in the atmospheres of the giant planets is thought to be representative of the protosolar composition, a quantity of high interest to cosmogonists and to cosmologists. The values of D/H range from about .0002 in the interstellar medium to .00016 in sea water here on Earth. The CH³D molecule was examined as a probe of the D/H ratio

[en] The paper presents fluorescence efficiency factors and absorption oscillator strengths for the A(2A1)-X(2B1) transition of H₂O(+). The abundance of H₂O(+) in the tail of comet Kohoutek 1973 XII is reassessed. The H₂O(+)/CO(+) ratio is determined to have been 0.8 + or - 0.2. 24 references

[en] Observations have been made of the 2--0 band of the Phillips system of interstellar C₂ toward the heavily obscured early-type stars VI Cygni No. 12, HD 29647, and BD +66⁰1675. The first direct proof that the rotational excitation temperatures of interstellar C₂ are nonthermal was obtained. Toward VI Cygni No. 12, the rotational distribution cannot be characterized by a single, unique excitation temperature; the distribution is consistent with radiative pumping models. A very strong linear correlation was found between N(C₂) and E/sub B/-V, which suggests that the relative abundance of C₂ is insensitive to a wide variation in physical conditions

[en] Spectrophotometric scans were obtained at 8 A resolution from 3295 to 8880 A on twenty nights before, during, and after the recent eclipse of epsilon Aurigae, beginning with a pre-eclipse observation on 5 March 1982 U.T. The observations were reduced to absolute flux using the standard stars 109 Vir or xi(2) Ceti. The data confirm that the eclipse is essentially gray over the entire visible spectrum, as others have noted from broadband photometry. High resolution echellograms (450 to 6700 A) made through mid-eclipse and the scans show changes in the equivalent widths of H alpha, Na D, and O I as large as a factor of two

[en] We report room-temperature laboratory studies of the 5520 A (6ν₁) and 6475 A (5ν₁) bands of self-broadened ammonia at column densities ranging from 1.7--435.7 meter-amagats (m-am). Detailed equivalent-width measurements at 24 different pressure-pathlength combinations corresponding to four pressures between 44 and 689 torr and pathlengths between 32 and 512 m are used to determin curves of growth and integrated band strengths. The band strengths for the 6ν₁ and 5ν₁ overtones are 5520 A: S=0.096 +- 0.005 cm^-1(m-am)^-1 and 6475 A: S=0.63 +- 0.03 cm^-1(m-am)^-1, respectively.Using these band strengths and curves of growth, we analyze new spatially resolved spectra of Jupiter showing a nonhomogeneous distribution of ammonia in the Jovian atmosphere. The observed variations in the CH₄/NH₃ mixing ratio are interpreted as evidence of altitude-dependent depletion of ammonia in the atmosphere

No abstract available

[en] Deuterium in the atmosphere of Uranus has been studied only via measurements of the exceedingly weak dipole lines of hydrogen-deuteride (HD) seen in the visible region of the spectrum. The other sensitive indicator of deuterium in the outer solar system is monodeuterated methane (CH3D) but the two bands normally used ot study this molecule, NU sub 2 near 2200 1/cm and NU sub 6 near 1161 1/cm, have not been detected in Uranus

[en] We report room-temperature laboratory studies of the red bands of methane at 40 different pressure--path-length combinations, corresponding to column densities between 0.024 and 3.897 km-amagat with pressures ranging between 0.10 and 2.00 atm. Detailed equivalent width measurements were used to determine curves of growth and integrated band strengths for the bands at 6190, 6825, 7050, and 7250 A. These measurements confirm the pressure independence of the methane curves of growth found by Lutz, Owen, and Cess for the blue-green bands and can be described by the same numerical curve of growth

No abstract available

[en] Selected long-slit spectrograms of Comet P/Halley, photographed during the postperihelion period between April 16 and June 3, 1910 have been quantitatively analyzed for comparison with the 1985/86 apparition. The Fe-V-Na spark spectrum was used to determine characteristic curves for these plates, and flux calibrations based on contemporaneous broad-band photometric measurements were applied. Haser model production rates for C2 and values Afp were computed for each of the nights selected and compared with the photometric observations obtained by Schleicher et al. (1987) during the comparable postperihelion period of the 1985/86 apparition. As found for the 1985/86 apparation, the gas and dust production in 1910 varied in phase, but the rates of production were higher than observed in 1986 by a small but statistically significant amount. 23 refs