An analysis of a stellar occultation by Neptune
A team at NMSU observed a stellar occultation by Neptune in July 2008 with the Astrophysical Research Consortium 3.5-meter telescope at Apache Point Observatory as shown in the animation. I fit the observed reduction of light as the star was occulted by Neptune to a simulation of an atmospheric body passing in front of a star. Among other parameters (including pressure, scale height, and atmospheric composition to name a few) the temperature of the upper stratosphere is determined from the best fit of the model to the observations.
We compared the temperature of Neptune determined in 2008 to temperatures of Neptune extracted using similar methods from occultations observed in the 1980's just before the Voyager 2 flyby. How the temperature changes as a function of latitudinal position, altitude, pressure, and time can be used to find the most significant long-term heating mechanisms in the upper stratosphere of Neptune.
The animation to the right depicts the stellar occultation by Neptune in July 2008. Neptune is the brightest object in the frame, followed by its moon Triton to the right of Neptune. Note: the actual duration of the event was roughly 2 hours, but has been sped up in this animation.
K. Uckert, N. J. Chanover, C. B. Olkin, L. A. Young, H. B. Hammel, C. Miller, J. M. Bauer. An investigation of the temperature variations in Neptune's upper stratosphere including a July 2008 stellar occultation event. Icarus, Vol. 232, pp 22-33, April 2014.
K. Uckert, N. Chanover, C. Miller, C. Olkin, L. Young, H. Hammel, J. Bauer. An Investigation of the Seasonal Changes of Neptune's Atmosphere via a July 2008 Stellar Occultation Event. The 44th Annual Meeting of the Division for Planetary Sciences of the American Astronomical Society, Vol. 44, Abstract #412.24, Reno, NV, October, 2012