1997/01/01 by H. A. Lam, S. Miller, R. D. Joseph +4 · 4 citations
Physics and Astronomy · #Astro and Planetary Science #Atomic and Molecular Physics #Scientific Research and Discoveries #Uranus #Physics #Brightness #Variation (astronomy) #Astrophysics #Astronomy #Spectral line #Jupiter (rocket family) #Emission spectrum #Wavelength #Brightness temperature #Planet #Optics
paper · pdf · doi:10.1086/310424
openalex publication_date 1997/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Infrared images of Uranus, obtained in 1993 April, at wavelengths sensitive to the H + 3 molecular ion, are presented. These show that spatial variation in the emission from the planet is discernible. Comparison with magnetic field modeling of Uranus indicates that sources of this variation may include auroral activity and other features, but the images show that the spatial variation is more limited than in the case of Jupiter. This conclusion is born out by spectra obtained on four consecutive nights during 1995 June, which show that the overall temporal variability of the H + 3 emission is ~20%. Comparison of the 1995 June spectra with data obtained in 1992, and the 1993 images, shows that the overall brightness of H + 3 emission of Uranus can vary by a factor of 2 on a timescale of years.