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Thrymr
	Discovery images of Thrymr (circled) taken by the CFHT in September 2000
Discovery
Discovery date	2000
Designations
Designation	Saturn XXX
Pronunciation	/ˈθrɪmər/ THRIM-ər
Named after	Thrymr
Alternative names	S/2000 S 7
Adjectives	Thrymian (/ˈθrɪmiən/ THRIM-ee-ən)
Orbital characteristics
Semi-major axis	20474000 km
Eccentricity	0.470
Orbital period (sidereal)	−1094.3 days
Inclination	176.0°
Satellite of	Saturn
Group	Norse group
Physical characteristics
Mean radius	4+50%; −30% km
Synodic rotation period	38.79±0.25? h
Albedo	0.06 (assumed)
Spectral type	C
Apparent magnitude	23.9
Absolute magnitude (H)	14.3

Thrymr (/ˈθrɪmər/ THRIM-ər), 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.^[3] Like Ijiraq and Kiviuq, Thrymr's orbit overlaps strongly with Phoebe's such that it is likely to collide with it in the future.^[4]

Its rotation period is 38.79±0.25 hours, the slowest among the retrograde moons measured by Cassini–Huygens and the second-slowest after Tarqeq.^[3] 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.^[4] 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.^[4] In particular, it may be part of the same dynamical family as Suttungr, though S/2004 S 7 is probably more closely related.^[4]