Ymir (moon)

Ymir /ˈmɪər/, or Saturn XIX, is the second-largest retrograde irregular moon of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 1. It was named in August 2003 after Ymir, who in Norse mythology is the ancestor of all the Jotuns or frost giants.[11]

Ymir
Discovery image of Ymir taken by the La Silla Observatory in August 2000
Discovery[1]
Discovered byBrett J. Gladman
Discovery siteObservatoire de la Cote d'Azur
Discovery date2000
Designations
Designation
Saturn XIX
Pronunciation/ˈmɪər/,[2] /ˈɪmɪər/[3]
Named after
Ymir
S/2000 S 1
AdjectivesYmirian /ɪˈmɪəriən/[4][5]
Orbital characteristics[6]
23,040,000 km
Eccentricity0.3349
3.6 yr (1315.14 d)
244.521°
Inclination173.125°
194.086°
22.668°
Satellite ofSaturn
GroupNorse group
Physical characteristics
Mean diameter
19+50%
−30%
 km
[7]
11.92220±0.00002 h[7]
11 h 55 m 20 s[8]
Albedo0.06[9]
Spectral type
D/P[8]
21.7[10]

    It takes 3.6 Earth years to complete an orbit around Saturn. Of the moons that take more than 3 Earth years to orbit Saturn, Ymir is the largest, at about 18 kilometres (11 miles) in diameter;[10] Ymir is also the second largest member of the Norse group, after Phoebe.[8]

    Spectral measurements from Cassini–Huygens show that Ymir is reddish in color, unlike Phoebe's gray color, suggesting a separate origin for this moon.[8] It shows a similar light curve as Siarnaq and has a triangular shape, rotating in a retrograde direction about once every 11.9 hours.[8]

    Ymir imaged by the CFHT on 23 September 2000

    References

    1. Brian G. Marsden (2000-10-25). "IAUC 7512". IAU. Retrieved 2011-01-08.
    2. "Ymir". Merriam-Webster.com Dictionary.
    3. Merriam-Webster's Encyclopedia of Literature. 1995.
    4. Budd (1898). "Norse Mythology". St. Mary's Hall lectures: and other papers. p. 84. Because the -r is an inflectional ending, and the oblique stem is Ymi (as in Modern Norse Yme), one might expect the English adjective to be ?Ymian, but that is perhaps too short a word to be easily intelligible.
    5. James Hall III (2015). Moons of the Solar System. p. 107.
    6. Jacobson, R.A. (2007) SAT270, SAT271 (2007-06-28). "Planetary Satellite Mean Orbital Parameters". JPL/NASA. Retrieved 2008-02-14.{{cite web}}: CS1 maint: multiple names: authors list (link)
    7. Denk, T.; Mottola, S. (2019). Cassini Observations of Saturn's Irregular Moons (PDF). 50th Lunar and Planetary Science Conference. Lunar and Planetary Institute.
    8. T. Denk, S. Mottola, F. Tosi, W.F. Bottke, D.P. Hamilton (2018). Schenk, P.M.; Clark, R.N.; Howett, C.J.A.; Verbiscer, A.J.; Waite, J.H. (eds.). The Irregular Satellites of Saturn (PDF). pp. 409–434. Bibcode:2018eims.book..409D. doi:10.2458/azu_uapress_9780816537075-ch020. ISBN 9780816537075. {{cite book}}: |journal= ignored (help)CS1 maint: multiple names: authors list (link)
    9. Nicholson, P. D. 2001
    10. Sheppard, Scott S. "Saturn's Known Satellites". Department of Terrestrial Magnetism. Retrieved 2008-02-14.
    11. Daniel W. E. Green (2003-08-08). "IAUC 8177: Sats OF (22); Sats OF JUPITER, SATURN, URANUS". IAU. Retrieved 2011-01-08.


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