Bestla
Bestla imaged by the Cassini spacecraft in September 2015
Discovery
Discovered byScott S. Sheppard
David C. Jewitt
Jan T. Kleyna
Brian G. Marsden
Discovery date2004
Designations
Designation
Saturn XXXIX
Pronunciation/ˈbɛstlə/
S/2004 S 18
Orbital characteristics [1]
20129000 km
Eccentricity0.521
−1083.6 days
Inclination145.2°
Satellite ofSaturn
GroupNorse group
Physical characteristics
Mean diameter
7+50%
−30% km[2]
14.6238±0.0001 h[2]
23.8

    Bestla /ˈbɛstlə/ or Saturn XXXIX is a retrograde irregular moon of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on 4 May 2005, from observations taken between 13 December 2004 and 5 March 2005.

    Description

    Bestla is about 7 kilometres in diameter, and orbits Saturn at an average distance of 20,192,000 km in 1088 days, at an inclination of 147° to the ecliptic (151° to Saturn's equator), in a retrograde direction and with an eccentricity of 0.5145.[3] Early observations from 2005 suggested that Bestla had a very high eccentricity of 0.77.[4] Like many of the outer irregular moons of the giant planets, Bestla's eccentricity may vary as a result of the Kozai mechanism. Bestla's rotation period is 14.6238±0.0001 hours.[2] Like Kiviuq, it is likely to be a contact binary or binary object, as its light curve has strong variation in brightness and a plateau-like maximum not seen in the other irregulars.[5]

    Name

    This moon was named in April 2007 after Bestla, a frost giantess from Norse mythology, who is a mother of Odin.

    References

    1. ↑ S.S. Sheppard (2019), Moons of Saturn, Carnegie Science, on line
    2. 1 2 3 Denk, T.; Mottola, S. (2019). Cassini Observations of Saturn's Irregular Moons (PDF). 50th Lunar and Planetary Science Conference. Lunar and Planetary Institute.
    3. ↑ Jacobson, R.A. (2007-06-28). "Planetary Satellite Mean Orbital Parameters". JPL/NASA. Retrieved 2008-01-19.
    4. ↑ Brian G. Marsden (2005-05-03). "MPEC 2005-J13 : Twelve New Satellites of Saturn". Minor Planet Center. Retrieved 2008-01-19.
    5. ↑ Denk, T.; Mottola, S.; Bottke, W. F.; Hamilton, D. P. (2018). "The Irregular Satellites of Saturn". Enceladus and the Icy Moons of Saturn (PDF). Vol. 322. University of Arizona Press. pp. 409–434. Bibcode:2018eims.book..409D. doi:10.2458/azu_uapress_9780816537075-ch020. ISBN 9780816537488.


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