| 词条 | Ymir (moon) |
| 释义 |
| bgcolour = #ffa812 | name = Ymir | image = | caption = | discovery_ref = [1] | discoverer = Brett J. Gladman | discovery_site = Observatoire de la Cote d'Azur | discovered = 2000 | alt_names = S/2000 S1, Saturn XIX | adjectives = Ymirian | orbit_ref = [2] | semimajor = 23,040,000 km | eccentricity = 0.3349 | period = 3.6 yr (1315.14 d) | inclination = 173.125° | mean_anomaly = 244.521° | arg_peri = 22.668° | asc_node = 194.086° | satellite_of = Saturn | dimensions = 18 km[3] | mass = 5.1{{e|15}} kg[4] | escape_velocity = 8.7 m/s (31 km/h)[4] | albedo = 0.06[5] | magnitude = 21.7[3] | rotation= 11 h 55 m 20 s[6] }}Ymir ({{IPAc-en|ˈ|ɪ|m|ɪər}} {{respell|IM|eer}}), or Saturn XIX, is a 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, from Norse mythology, where Ymir is the ancestor of all the Jotuns or frost giants.[7] Of the moons that take more than 3 Earth years to orbit Saturn, Ymir is the largest, at about {{convert|18|km|mi|abbr=off}} in diameter.[3] It takes 3.6 Earth years to complete an orbit around Saturn. During this time, hypothetical Ymir visitors would experience ~2650 sunsets. References1. ^{{cite web |date=2000-10-25 |title=IAUC 7512 |publisher=IAU |author=Brian G. Marsden |url=http://www.cbat.eps.harvard.edu/iauc/07500/07512.html |accessdate=2011-01-08}} 2. ^{{cite web |date=2007-06-28 |title=Planetary Satellite Mean Orbital Parameters |publisher=JPL/NASA |author=Jacobson, R.A. (2007) SAT270, SAT271 |url=http://ssd.jpl.nasa.gov/?sat_elem#saturn |accessdate=2008-02-14}} 3. ^1 2 {{cite web |title=Saturn's Known Satellites |publisher= Department of Terrestrial Magnetism |author=Scott S. Sheppard |author-link=Scott S. Sheppard |url=http://www.dtm.ciw.edu/users/sheppard/satellites/satsatdata.html |accessdate=2008-02-14}} 4. ^1 assume radius of 9 km; volume of a sphere * assume density of 1.7g/cm³ (though it could be a loose rubble pile) yields a mass of 5.1e15 kg and an escape velocity of 8.7 m/s (31 km/h) 5. ^Nicholson, P. D. 2001 6. ^T. Denk, S. Mottola, F. Tosi, W.F. Bottke, D.P. Hamilton (2018): [https://tilmanndenk.de/wp-content/uploads/DenkEtAl2018_IrregularMoons.pdf The Irregular Satellites of Saturn.] In: Enceladus and the Icy Moons of Saturn, Schenk, P.M., Clark, R.N., Howett, C.J.A., Verbiscer, A.J., Waite, J.H. (eds.), Space Science Series, The University of Arizona Press, Tucson, AZ. Chapter 20, p. 409-434. [https://doi.org/10.2458/azu_uapress_9780816537075-ch020 DOI:10.2458/azu_uapress_9780816537075-ch020.] 7. ^{{cite web |date=2003-08-08 |title=IAUC 8177: Sats OF (22); Sats OF JUPITER, SATURN, URANUS |publisher=IAU |author=Daniel W. E. Green |url=http://www.cbat.eps.harvard.edu/iauc/08100/08177.html |accessdate=2011-01-08}} External links{{Commons category|Ymir (moon)}}
2 : Moons of Saturn|Astronomical objects discovered in 2000 |
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