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Carbon Chain Anions and the Growth of Complex Organic Molecules in Titan’s Ionosphere
DOI: 10.3847/2041-8213/aa7851 Bibcode: 2017ApJ...844L..18D

Lewis, G. R.; Coates, A. J.; Kataria, D. O. +13 more

Cassini discovered a plethora of neutral and ionized molecules in Titan’s ionosphere including, surprisingly, anions and negatively charged molecules extending up to 13,800 u q-1. In this Letter, we forward model the Cassini electron spectrometer response function to this unexpected ionospheric component to achieve an increased mass res…

2017 The Astrophysical Journal
Cassini 40
Corotating Magnetic Reconnection Site in Saturn’s Magnetosphere
DOI: 10.3847/2041-8213/aa88af Bibcode: 2017ApJ...846L..25Y

Lewis, G. R.; Coates, A. J.; Dougherty, M. K. +12 more

Using measurements from the Cassini spacecraft in Saturn’s magnetosphere, we propose a 3D physical picture of a corotating reconnection site, which can only be driven by an internally generated source. Our results demonstrate that the corotating magnetic reconnection can drive an expansion of the current sheet in Saturn’s magnetosphere and, conseq…

2017 The Astrophysical Journal
Cassini 25
Nanograin Density Outside Saturn’s A Ring
DOI: 10.3847/2041-8213/834/1/L6 Bibcode: 2017ApJ...834L...6J

Persoon, A. M.; Johnson, Robert E.; Tseng, Wei-Ling +1 more

The observed disparity between the radial dependence of the ion and electron densities measured by the Cassini plasma (CAPS) and radio (RPWS) science instruments are used to show that the region between the outer edge of Saturn’s main rings and its tenuous G ring is permeated with small charged grains (nanograins). These grains emanate from the ed…

2017 The Astrophysical Journal
Cassini 5
Photoionization Modeling of Titan’s Dayside Ionosphere
DOI: 10.3847/2041-8213/aa998d Bibcode: 2017ApJ...850L..26S

Wahlund, J. -E.; Edberg, N. J. T.; Vigren, E. +4 more

Previous modeling studies of Titan’s dayside ionosphere predict electron number densities that are roughly a factor of 2 higher than those observed by the RPWS/Langmuir probe. The issue can equivalently be described as the ratio between the calculated electron production rates and the square of the observed electron number densities resulting in r…

2017 The Astrophysical Journal
Cassini 4
A Librational Model for the Propeller Blériot in the Saturnian Ring System
DOI: 10.3847/2041-8213/aa6d73 Bibcode: 2017ApJ...840L..16S

Seiß, M.; Spahn, F.; Hoffmann, H. +2 more

The reconstruction of the orbital evolution of the propeller structure Blériot orbiting in Saturn’s A ring from recurrent observations in Cassini ISS images yielded a considerable offset motion from the expected Keplerian orbit. This offset motion can be composed by three sinusoidal harmonics with amplitudes and periods of 1845, 152, 58 km and 11.…

2017 The Astrophysical Journal
Cassini 4