MOLECULAR HYDROGEN IN THE SPECTRA OF URANUS AND NEPTUNE

Abstract

In August and September 2017, on the 2-meter telescope of ShAO by using a fiber-optic echelle spectrograph (ShaFES) with dierent spectral resolutions: R = 28000 and R = 56000, the spectra of Uranus and Neptune were obtained. In the spectra of these planets, absorption lines of molecular hydrogen H2 in the bands (4-0) λ6435.03 Å and 6367.76 Å were studied, and line S4(2)
was found. The upper limits of the absorption line intensity in the spectra of Uranus and Neptune were determined. Pressure values (P = 2,1÷2,4 atm for Uranus, and P = 2÷2,3 atm for Neptune) by half-breadth of the lines λ6367.76 Å and λ6435.03 Å, in the (4-0) band of molecular hydrogen, in the spectra of Uranus and Neptune were estimated. Additionally, the rotational temperature (90◦ ±12K for Uranus, 101◦ ±10 K for Neptune) was determined by the ratio of the intensities of these lines at the depth at which these lines are formed. Dynamical processes occurred on Uranus can be damping processes. The nature of the circulation in the atmosphere of Neptune is regulated "from below," from the planetary interior. Such non-stationary processes cause changes in the density of aerosol particles and their distribution on height in its atmosphere, temperature, and movement rate in the clouds.