TRAPPIST OBSERVATIONS OF SODIUM JETS FROM IO

Abstract

Our study of fast sodium jets from Io with the TRAPPIST-South telescope, spanning four months of observation from December 4, 2014 to March 31, 2015, begins with the acquisition and the reduction of the raw data. The optics of the telescope and the very powerful brightness of Jupiter produce artifacts on the images still present after calibration. We used several image processing methods to improve the signal-to-noise ratio and clean our reduced images in order to optimize the region where a jet would be located and to optimize our measurements. Among the fifteen observations nights, we observed six nights with sodium jets coming from Io. Then, we measured the length of all detected jets, extending over several Jovian radii, and the angle with the Jupiter-Io line. The night of December 4, 2014 is the most impressive, the extent of the detected jet is approximately seven Jovian radii. This first study allows us to improve the next observations with the ultimate aim of observing these jets and finally improve our understanding about them.