Thrymr (moon)

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Thrymr (Template:IPAc-en Template:Respell), or Saturn XXX, is a natural satellite of Saturn. It was discovered by Gladman and colleagues in 2000, and given the temporary designation S/2000 S 7. Its name comes from Norse mythology, where Thrymr is a Jotun.

Thrymr is about 8 kilometres in diameter, and orbits Saturn at an average distance of 20,810 Mm in 1120.809 days. It may have formed from debris knocked off Phoebe. The Thrymian orbit is retrograde, at an inclination of 175° to the ecliptic (151° to Saturn's equator) and with an eccentricity of 0.453.<ref name="LPSC2654"/> Like Ijiraq and Kiviuq, Thrymr's orbit overlaps strongly with Phoebe's such that it is likely to collide with it in the future.<ref name="Denk2018">Template:Cite book</ref>

Its rotation period is Template:Val hours, the slowest among the retrograde moons measured by Cassini–Huygens and the second-slowest after Tarqeq.<ref name="LPSC2654">Template:Cite conference</ref> Having two maxima and two minima in its light curve, it may therefore be a contact binary, although this is less likely than for Kiviuq and Bestla.<ref name="Denk2018"/> The surface of Thrymr is gray in color and similar to those of Suttungr and Mundilfari, suggesting a common origin as fragments knocked off of Phoebe early in the Solar System's history.<ref name="Denk2018"/> In particular, it may be part of the same dynamical family as Suttungr, though S/2004 S 7 is probably more closely related.<ref name="Denk2018"/>

Its name was announced in its oblique form Thrym in IAU Circular 8177. However, the IAU Working Group on Planetary System Nomenclature later decided to add the nominative suffix -r to the root Thrym.