Pluto Stellar Occultation

The 2015 stellar occultation by Pluto of a background star with an r-band of magnitude ~12 was captured by FPI+ as a light curve, showing the decreased signal (in magnitudes) during the event. The central flash in the middle of the light curve confirms the precise position of SOFIA on the centerline of the shadow path, allowing for analysis of the upper atmosphere. This results in a best-fit value for the occultation half-light radius of 1288±1 km (i.e., the radius in the atmosphere at which the occultation light curve drops to half its original flux due to refraction).

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