Abstract
Neptune and Uranus are observed with Keck II NIRSPEC in an attempt to detect H+3 emission from Neptune. In this set of observations, H+3 emission remains undetected at Neptune, whereas line-resolved emission from Uranus was observed with a signal-to-noise ratio of ∼100. Using this, we have derived an upper limit of the column-integrated H+3 density on Neptune of 1.5 (+4.8−0.9)× 1013 m−2, assuming a temperature of 550±100 K. This value improves the previous established limit by a factor of 20 and shows that the H+3 density predicted by the best available model overestimate the density by at least a factor of 3.
In addition, the solar reflection continuum of Neptune in the K and L′ bands is seen to be brighter on the Northern hemisphere by a factor of ∼2, whereas previous observations had noted the solar reflection as being brighter on the Southern hemisphere.
In addition, the solar reflection continuum of Neptune in the K and L′ bands is seen to be brighter on the Northern hemisphere by a factor of ∼2, whereas previous observations had noted the solar reflection as being brighter on the Southern hemisphere.
Original language | English |
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Pages (from-to) | 641-644 |
Number of pages | 4 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 410 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 2011 |
Externally published | Yes |