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/ˈiːmɪər/,[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]

    Ymir /ˈiːmɪər/, 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]

    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) CS1 maint: numeric names: authors list (link)
    7. 1 2 Denk, T.; Mottola, S. (2019). Cassini Observations of Saturn's Irregular Moons (PDF). 50th Lunar and Planetary Science Conference. Lunar and Planetary Institute.
    8. 1 2 3 4 5 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). Space Science Series, The University of Arizona Press, Tucson, AZ. Chapter 20. 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. 1 2 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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