Astronomy:Greip (moon)
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 |
S/2006 S 4 | |
Orbital characteristics [1] | |
18206000 km | |
Eccentricity | 0.326 |
Orbital period | −921.2 days |
Inclination | 179.8° |
Satellite of | Saturn |
Group | Norse group |
Physical characteristics | |
Mean diameter | 5+50% −30% km[2] |
Rotation period | 12.75±0.35? h[2] |
Apparent magnitude | 24.4 |
Greip /ˈɡreɪp/ or Saturn LI is a natural satellite of Saturn. 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 6 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 Suttungr or Hyrrokkin 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
- ↑ S.S. Sheppard (2019), Moons of Saturn, Carnegie Science, on line
- ↑ 2.0 2.1 2.2 Denk, T.; Mottola, S. (2019). "Cassini Observations of Saturn's Irregular Moons". 50th Lunar and Planetary Science Conference. Lunar and Planetary Institute. https://www.hou.usra.edu/meetings/lpsc2019/pdf/2654.pdf.
- ↑ 3.0 3.1 3.2 Denk, T.; Mottola, S.; Bottke, W. F.; Hamilton, D. P. (2018). "The Irregular Satellites of Saturn". Enceladus and the Icy Moons of Saturn. 322. University of Arizona Press. pp. 409–434. doi:10.2458/azu_uapress_9780816537075-ch020. ISBN 9780816537488. Bibcode: 2018eims.book..409D. https://tilmanndenk.de/wp-content/uploads/DenkEtAl2018_IrregularMoons.pdf.
- Institute for Astronomy Saturn Satellite Data
- IAUC 8727: Satellites of Saturn[yes|permanent dead link|dead link}}] June 30, 2006 (discovery)
- MPEC 2006-M45: Eight New Satellites of Saturn June 26, 2006 (discovery and ephemeris)
- IAUC 8873: Satellites of Saturn[yes|permanent dead link|dead link}}] September 20, 2007 (naming)
Original source: https://en.wikipedia.org/wiki/Greip (moon).
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