Contents

Greip (moon)

Moon of Saturn

Greip

Greip imaged by the Cassini spacecraft in September 2015
Discovery
Discovered by	Scott S. Sheppard David C. Jewitt Jan T. Kleyna Brian G. Marsden
Discovery date	2006
Designations
Designation	Saturn LI
Named after	Greipa
Alternative names	S/2006 S 4
Orbital characteristics[1]
Semi-major axis	18206000 km
Eccentricity	0.326
Orbital period (sidereal)	−921.2 days
Inclination	179.8°
Satellite of	Saturn
Group	Norse group
Physical characteristics[2][3]
Mean diameter	5+50% −30% km
Synodic rotation period	12.75±0.35? h
Albedo	0.06 (assumed)
Apparent magnitude	24.4
Absolute magnitude (H)	15.4

Greip /ˈɡreɪp/orSaturn LI is a natural satelliteofSaturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on 26 June 2006, from observations taken between 5 January and 1 May 2006. Greip is about 5 kilometres in diameter, and orbits Saturn at an average distance of 18,066 Mm in 906.556 days, at an inclination of 172.7° to the ecliptic (159.2° to Saturn's equator), in a retrograde direction and with an eccentricity of 0.3735, and is presumably at high risk of eventually colliding with Phoebe.^[3] It is unknown whether Greip is more similar to SuttungrorHyrrokkin in color.^[3] Its rotation period is most likely 12.75±0.35 hours with two minima in the light curve,^[2] but a longer period of 19 hours cannot be ruled out due to the short observation time by Cassini–Huygens.^[3]

It is named after Greip, a giantess in Norse mythology.

References[edit]

External links[edit]

• Institute for Astronomy Saturn Satellite Data
• IAUC 8727: Satellites of Saturn June 30, 2006 (discovery)
• MPEC 2006-M45: Eight New Satellites of Saturn June 26, 2006 (discovery and ephemeris)
• IAUC 8873: Satellites of Saturn September 20, 2007 (naming)